Category Archives: Beach of the Month

“Beach Robbers”; By Charles O. Pilkey

Chapter 5: Beach Robbers

Written and illustrated by Charles O. Pilkey ©2018.

This Chapter is excerpted from The Magic Dolphin: A Young Human’s Guide to Beaches, Sea Level Rise and Living with the Sea; A Book By Charles O. Pilkey With Orrin H. Pilkey.

Copyright ©2018 by Charles O. Pilkey and Orrin H. Pilkey. All rights reserved.
Used by permission of the publisher, courtesy of Charles and Orrin Pilkey, for Coastal Care.

California’s Coastal Harbors, Beach Compartments and Sand Dredging; By Gary Griggs

By Gary Griggs, Distinguished Professor of Earth and Planetary Sciences, Director Institute of Marine Sciences, University of California, Santa Cruz, California

Every year the dredge at the Santa Cruz Small Craft Harbor along central California’s northern Monterey Bay sucks up about 250,000 cubic yards of sand, on average, from the entrance channel and pumps it out onto Twin Lakes Beach where it continues its journey down coast (Figure 1). If it were put in dump trucks, it would fill about 25,000 of them, but the waves can move all that sand without any human labor, and without any noise or carbon emissions. The waves, however, can’t easily move it across the harbor entrance without the channel plugging it up.

The sand moving along the Santa Cruz coastline starts its shoreline journey about 75 miles upcoast, 15 miles south of San Francisco’s Golden Gate. Sand reaches the beaches of this section of coastline from small creeks and rivers and from the erosion of the sandy bluffs. After being carried southward by breaking waves from the northwest, down the San Mateo and Santa Cruz County coasts, it enters Monterey Bay (Figure 2).

The beach immediately upcoast of the harbor was much narrower under natural conditions (Figure 3), but with the completion of the Santa Cruz harbor in 1965, the new jetties became a dam for littoral drift. The beach immediately upcoast of the harbor (known historically as Castle Beach because of an old castle built on a low bluff (Figure 4), but today more often known as Seabright Beach), widened by as much as 500 feet as millions of cubic yards of sand were trapped behind the jetty over the next several decades (Figure 5).

“The dredging is an endless and thankless task, but we really don’t have much choice if we want to maintain the harbor… ”
— Gary Griggs

Within a few years, however, some of that littoral sand was carried by the northwesterly waves around the end of the west jetty into the entrance of the new harbor. Deposition of the sand soon led to shoaling of the boat channel and threatened to close the harbor. Dredging was needed and has been needed ever since (Figure 6). Nine and a half million cubic yards of sand were dredged out between 1964 and 2014, enough to fill the entire Superdome in New Orleans twice.

The dredging is an endless and thankless task, but we really don’t have much choice if we want to maintain the harbor. If its any consolation, many other California coastal harbors share the same problem – how to deal with all the littoral sand that continues to move into their entrance channels on its path down along the shoreline.

Santa Barbara harbor dredges a bit more than Santa Cruz, about 310,000 cubic yards every year on average (Figure 7). A short distance down coast, Ventura harbor must move about 600,000 cubic yards a year (Figure 8). A few miles farther east, Channel Islands Harbor dredges close to a million cubic yards, every year (Figure 9). The sand removed from Channel Islands Harbor has already been
pumped out of the Santa Barbara and Ventura harbors, so is eventually dredged out of three different harbors. At $5 a cubic yard or more, these are high annual maintenance costs. And the problem will never go away and will gradually get more expensive as fuel and labor costs increase over time.

Not all of California’s harbors have sand and dredging problems. Neither Moss Landing (Figure 10) nor Monterey harbors (Figure 11) do any significant dredging. King Harbor in Redondo Beach doesn’t need to move sand (Figure 12), and Dana Point Harbor has never been dredged (Figure 13). Why is that? Why do we have to move 250,000 cubic yards of sand every year out of the Santa Cruz Harbor, and 20 miles away, Moss Landing has an entrance channel that doesn’t need to be dredged? Just like real estate, it’s all about location, location, location.

Sand moves along the shoreline of California and along many coastlines around the world within essentially self – contained beach compartments or littoral cells. The sand that moves along the shoreline of northern Monterey Bay is in a completely different compartment than the sand coming out of the Golden Gate or found along the beaches of Santa Barbara or Santa Monica.

Each cell or compartment consists of 1) sources of beach sand (rivers, streams and some bluff erosion along California’s coast); 2) littoral drift or longshore transport, driven by waves typically coming from the northwest, which move sand southward along most of the California coastline; and 3) sinks, or places where sand leaves the shoreline (Figure 14). In California the major sinks are either sand dunes, such as those along the shoreline of southern Monterey Bay or Pismo Beach, where wind transports the sand inland off the beach; or deep submarine canyons, where sand flows offshore and down slope to the deep – sea floor 10,000 to 12,000 feet below.

“Moss Landing, Monterey, King, and Dana Point harbors are all good examples of low or no maintenance harbors because of their locations… ”
— Gary Griggs

Monterey Submarine Canyon, which bisects Monterey Bay (Figure 15), is one of the largest in the world, but there are many others along the California coast that also serve as sinks for beach sand: Carmel Canyon, Hueneme Canyon, Mugu Canyon, Redondo Canyon and Newport Canyon to name a few (Figure 16). The Santa Cruz beach compartment begins north of Half Moon Bay and terminates at Moss Landing where the head of Monterey Canyon extends almost to the beach. After being transported for 90 miles along the shoreline, the sand that began its journey near San Pedro Point, about 15 miles south of the Golden Gate, disappears offshore right at the entrance to Moss Landing harbor (Figure 17). As a result, very little sand enters the harbor so there is almost no dredging needed.

The beach sand in the Santa Barbara littoral cell is carried by longshore transport about 145 miles from north of Pt. Conception to the Mugu Submarine Canyon near Pt. Mugu. Along this route the sand is trapped in three different harbors, where it must be dredged our regularly, and is augmented by sand from two large rivers, the Ventura and Santa Clara. The littoral drift rate is about a million cubic yards a year near the downcoast end of the cell at the Channel Islands Harbor. This translates to huge annual dredging costs.

Wherever harbors have been constructed in the middle or downcoast ends of beach compartments with high littoral drift rates, annual and costly dredging of large volumes of sediment is inevitable if the harbor entrances are to be kept open for boats year round.

Where harbors have been built either between beach compartments, however, or at the upcoast ends of cells where littoral transport rates are still low, maintenance dredging is minimal or not required at all. Moss Landing, Monterey, King, and Dana Point harbors are all good examples of low or no maintenance harbors because of their locations. Moss Landing and King harbors were located adjacent to submarine canyons, Monterey Submarine Canyon and Redondo Submarine Canyon respectively. Almost no sand enters either harbor from the beach. Monterey and Dana Point were placed at the beginning of littoral cells and have virtually no dredging costs.

We can think of these beach compartments like bank accounts. Sand or money go in or are deposited, and sand or money go out, whether as cash, checks, or credit cards. As long as the amount of sand or money leaving the cell or being taken out of the account isn’t greater than what is being deposited or coming in, the account is in balance and the beaches remain stable. However, wherever the flow of sand into the compartment is trapped, whether by dams, debris basins, or sediment removal on rivers or streams, or interrupted or removed as it moves through the compartment, by the construction of long jetties or breakwaters along the coastline, or sand mining from the beach, the bank account is overdrawn and beach erosion and shoreline retreat will result.

Beyond Preservation: The Coral Restoration Foundation Bonaire; By Andrew Jalbert

By Andrew Jalbert

Originally published in Diver Magazine, 2017.
All text and image courtesy of © Andrew Jalbert. All rights reserved.

When avid scuba diver and famed Jurassic Park author Michael Crichton first visited Bonaire decades ago, he eloquently described the underwater environment as, “a world of riotous, outrageous color.” Years later, Bonaire has seen some changes but his assessment still largely rings true. From its protected nearshore reef system and calm seas to its first-rate dive facilities, Bonaire has become one of the world’s premiere destinations for scuba enthusiasts. The combination of seemingly unlimited shore diving options and the island’s dedication to marine preservation provides divers with the freedom to explore a healthy environment at their own pace.

The local government, non-governmental agencies, and private businesses alike have all worked diligently to earn the Divers Paradise slogan Bonaire displays on its automobile license plates. Their economy is largely driven by scuba and other eco-tourism. To that end, protecting the island’s ecology is more than just a noble cause; it’s good business. The reef is Bonaire’s gem⎯one of the main draws to the island, and nearly every resident has a stake in its preservation to some degree. It’s comprised of over fifty species of coral, starting just beyond the shoreline and extending 300 meters offshore.

“What can be done when coral populations are being destroyed by factors beyond the reach of local regulations?The Coral Restoration Foundation Bonaire (CRFB) seems to have an answer for that.”
— Andrew Jalbert

This entire area was designated as the Bonaire National Marine Park in 1979 and has been protected accordingly ever since: Spear fishing is prohibited (with the exception of recent efforts to harvest invasive Lionfish), there is no collecting allowed (of anything, dead or alive including seashells or broken pieces of coral), no use of gloves, and no disturbing the turtles, their nests, or their eggs. Even chemical glow sticks for night diving (commonly used elsewhere) are prohibited. There are other regulations that apply to anchoring, fishing, shoreline structures, sand extraction, tree cutting, and campfires; all designed to ensure the health of the island’s environment. It’s an effective model for eco-tourism that’s been working successfully for decades.

Unfortunately, there are larger scale threats to these ecosystems, both human-caused and natural, that cannot be avoided simply by practicing good buoyancy or refraining from spear fishing. Disease, hurricanes, pollution, bleaching, acidification and rising water temperatures have all destroyed vast expanses of corals over the past several decades throughout the world. With the loss of healthy coral comes the loss of habitat⎯one of the quickest ways to displace countless other marine animals. These threats were highlighted recently by an article in Outside magazine titled, “Obituary: Great Barrier Reef (25 Million BC-2016).” The article proclaimed that Australia’s famous reef had been damaged beyond recovery by ocean acidification and warming water temperatures. Although scientists offered varying responses to the article’s predictions the message was very clear: the oceans’ coral reefs are in trouble.

While Bonaire’s strict preservation efforts have successfully shielded its reef from localized threats, the larger scale issues have still taken a toll. The shallow water Staghorn and Elkhorn corals (Acropora cervicornis and Acropora palmate respectively) in particular have seen a rapid decline since the 1980s. Both species of coral were listed as threatened by the National Oceanic and Atmospheric Administration (NOAA) in 2006 and by 2012, the classification had been elevated to endangered. It’s a phenomenon that many of us who are long time visitors to Bonaire have witnessed over the years: The large stands of these corals that were once so prevalent along the shallow, nearshore plateaus have become fields of white rubble.

There isn’t a single factor to blame for this decline but rather, a combination of events that began in the late 1970s when an outbreak White-Band Disease sharply decreased Elkhorn and Staghorn populations. The following decade, a mass die-off of the long-spined black sea urchin, (the “lawnmowers of the reef”) left algae largely unchecked resulting in overgrowth that further stressed the populations. Finally, threats associated with climate change including ocean acidification (a decrease in the ocean’s pH levels caused by atmospheric carbon dioxide being dissolved into the water) and warmer ocean temperatures have led to increased coral bleaching (a phenomenon in which polyps expel essential plant cells leaving corals weak and less capable of fighting disease and other stresses) that put these populations at risk of collapse. With the steady disappearance of these corals comes a rather daunting realization: If the threats are large-scale, preservation laws alone may not be enough. What can be done when coral populations are being destroyed by factors beyond the reach of local regulations? The Coral Restoration Foundation Bonaire (CRFB) seems to have an answer for that: You try to restore them.

The story of the CRFB doesn’t actually begin in Bonaire at all, but rather in Key Largo, Florida. It was here in 2003 that the first nursery-reared Staghorn Coral was transplanted back onto Molasses Reef. By 2007, the non-profit Coral Restoration Foundation (CRF) had been founded. Realizing that the problem was widespread and seeing the success of the program, CRF developed a mission that focused on “educating, inspiring, and empowering people around the world to be proactive and make a difference on their own coral reefs.” In 2012, CRFB was established and granted the appropriate permits to help Buddy Dive Resort create a pilot nursery on Buddy’s Reef and another off the coast of Klein Bonaire; the small islet set less than a Kilometer to the west. Within a year, the first nursery-reared corals were on their way back to Bonaire’s reef.

In true Bonarian fashion, CRFB has been pushing back against environmental threats and doing so at the local level. It’s been a targeted effort that (if current data is any indication) is proving very successful. By creating Staghorn and Elkhorn nurseries and subsequently transplanting the corals back to the shallow seafloor, CRFB has to date, reintroduced nearly 10,000 healthy, rapidly propagating coral fragments.
The success of the program in Bonaire is something that the foundation’s Assistant Project Coordinator Bridget Hickey is clearly proud of. I met Bridget at Blenny’s Restaurant at Buddy Dive Resort in February as she was busily preparing a presentation about coral restoration and the history of their organization on Bonaire. When the presentation was finished, I had the chance to talk to her about the topic I was most curious about: their methods.

“Although coral reefs are often described using flora-related words such as “gardens” or “forests” nearly every part of these sprawling structures are animals, or at very least, their creation. ”
— Andrew Jalbert

Although coral reefs are often described using flora-related words such as “gardens” or “forests” nearly every part of these sprawling structures are animals, or at very least, their creation. Nonetheless, the restoration process is remarkably similar to gardening, albeit at a much slower rate. The corals can be propagated like a plant by fragmentation (taking small pieces from healthy coral), which creates exact genetic replicas of the parent coral. These fragments are then hung in midwater on PVC “nursery trees” using monofilament line. This not only provides safety from predators but it allows the coral to grow in all directions. As they grow, they are pruned to create second and third generation fragments which are similarly hung. Within 8-12 months, the coral fragments have grown to a suitable size and health (referred to as being “reef competent”) for transplantation. They are then removed from the trees and replaced by newer, smaller fragments. At any given time, there are more than 8000 of these fragments growing throughout the Bonaire nurseries.

These “reef competent” fragments are attached to the seafloor using one of two methods. The first is to glue them to a hard substrate using a marine epoxy. As the corals grow, they will create their own foundations on the rock below. In areas where a hard substrate doesn’t exist, the coral fragments are tied to pre-built frames that sit on the sand or rubble. These frames are raised off the seafloor to give the transplanted corals time to strengthen and fuse before being exposed to bottom predators. Both transplantation methods are used for the rapidly growing Staghorn coral however the much denser Elkhorn corals are reintroduced on hard substrate only using epoxy.

There are currently 70 trees within five nurseries on Bonaire, all tended by CRFB, trained volunteers, and sponsoring dive shops. Eight restoration sites are spread out along the western shore of the island and around Klein Bonaire. The restoration sites are not chosen randomly but instead are researched to identify factors that will make the new colony’s success more likely. These include water quality, depth, historical presence of the corals, space competition, and predation. Under Bridget’s direction I visited a couple of these restoration sites and was both surprised and encouraged by what I saw: The more established sites had developed into dense thickets teeming with small fish and if not for the presence of the barely visible framework below, I would have assumed they were natural stands. The pace is slow, but fragment by fragment, portions of the reef are being rebuilt and are flourishing.

For those of us concerned about of the health of the oceans, the news lately has been discouraging. The entire matter is more than a bit overwhelming to think about and, as is so often the case with large-scale problems, it’s difficult to know how to do something that provides tangible results. Perhaps the answers lie not in a single, broad-sweeping solution but rather, in several smaller ones. By adhering to the original mission to “be proactive and make a difference on their own coral reefs,” CRFB is facing environmental issues head on; not on a worldwide scale but locally. The efforts may not offer a complete solution, but they are undoubtedly part of it.

To learn more about the Coral Restoration Foundation Bonaire and find out how to help please visit: Coral Restoration Foundation Bonaire.

Management Strategies for Coastal Erosion Processes; By Nelson Rangel-Buitrago

Abstract By Nelson Rangel-Buitrago, Grupo de Geología, Geofísica y Procesos Marino-Costeros, Universidad del Atlántico Barranquilla, Atlántico, Colombia

Originally published in the “Ocean Coastal and Management Journal,” issue 156; Science Direct. All text and image courtesy of © Nelson Rangel-Buitrago. All rights reserved.

The Special Issue Management Strategies for Coastal Erosion Processes (MSforCEP) presents an international collection of papers related to the implementation of various management strategies for coastal erosion under specific objectives:

      • Identification of significant coastal erosion issues.
      • Understanding of the underlying coastal processes contributing to erosion problems.
      • Development and evaluation of strategies for the adequate coastal erosion management.
      • Facilitation of community input on coastal erosion issues.
      • Assistance in coastal planning for the delivery of optimal erosion management options.

The SI objective is to make a clear and explicit link between fundamental concepts and the improvement of coastal erosion management practice. To reach this goal, papers presented in this special issue are grouped into four main topics:

      • Policies.
      • Management Practices.
      • Methodological Approaches.
      • New Alternatives in the Coastal Erosion Management.

The first paper “The Management of Coastal Erosion” (Williams et al.) presents an in depth analysis of coastal erosion management theory, as well as, giving many examples of the various options available to manage erosion. To the standard trio of defend, sacrifice, and realignment strategies is added a fourth strategy: ‘intervention as to the causes.’

Under the topic ‘Policies for coastal erosion management’ two papers are presented from the USA. ‘Why coastal regulations fail’ (Neal et al.) and ‘Coastal erosion and the United States Flood Insurance Program’ (Leatherman). These papers show both the general weaknesses of regulations as well as how some specific programs have failed in part due to legal flaws, and also in part for not including projected rates of sea-level rise and erosion.

The ‘Coastal erosion management practices’ section includes papers from Italy (Pranzini), Colombia (Rangel et al.), Kuwait (Neelamani), West Africa (Ndour et al.), Argentina (Isla et al.) and the USA(Nordstrom et al.). These papers confirm that coastal erosion is a rising worldwide problem, and reflect how many management practices have not been used very successfully or have failed in their purpose. The conclusion is that under current coastal development practices and climate change conditions, smart, innovative and strong coastal erosion management plans are needed.

The ‘Methodological approaches section’ includes detailed case studies from Bulgaria (Stanchev et al.), Chile (Martinez et al.), Mexico (Escudero-Castillo et al.), Saint Kitts (Stancioff et al.), USA (Psuty et al.), Brazil (Bonetti et al.) and Malta (Micallef et al.). These papers include methodologies such as i) analysis of shoreline changes by satellite images, ii) beach profiling, iii) geo-indicators and iv) the Coastal Hazard Wheel: all used as tools that provide reliable data and useful information for coastal erosion management.

Lastly, the section called ‘New alternatives in the coastal erosion management’ encompasses a review article (Gracia et al.) and four case studies from Croatia (Pikelj et al.), Portugal – the Netherlands (Stronkhorst et al.), India (Ramakrishnan et al.) and West Africa (Giardino et al.). These five papers conclude that coastal erosion management using new approaches can be cost-effective and sustainable, but the success of these kinds of strategies will depend on the determination of realistic operational objectives and indicators.

The world urgently requires effective management strategies to help solve the present coastal erosion problem. The use of one strategy by itself cannot guarantee a 100% success rate; the combination of different strategies seems a promising way forward. Management strategies for coastal erosion must be included and not overlooked in any coastal planning scheme.

Within the last few years, new approaches have received much attention, but there are still many areas in research, education, and practice that must be covered. As climate change raises the risk and incidence of coastal hazards, it is imperative that all involved stakeholders continue to examine their role and participation in the coastal erosion management process.

Sand volcanos on a flat and sandy beach in the Netherlands; By Bert Buizer, PhD

By Bert Buizer, PhD

Introduction

In general, the west coast of the Netherlands is oriented south – north and is characterized by sandy and flat beaches, popular for tourists all year round.

In contrast, the south western estuarine area is mostly lined by artificial stony dikes to protect the low lying land from the sea. After the 1953 storm surge, killing over 1800 people, most of the estuaries were entirely closed. However one of the estuaries, the Eastern Scheldt, was only partly closed, and now offers an excellent habitat for newly settled marine species. They possibly settled either as a result of (geographic) range extension related to climate change, or have migrated to the area by (macro)fouling on ships’ hulls or been inadvertently ferried in ballast water.

Only the most southern estuary, the Western Scheldt, was left completely open allowing access to the port of Antwerp, Belgium.

The north eastern area of the Dutch coast is part of the Dutch – German – Danish Wadden Sea features distinctively muddy areas with exceptional ecosystems.

However, in this Beach of the Month article, we focus on that part of the North Sea coast that mainly consists of 100% mineral sand without any rocks and only some artificial hard substrates.

At low tide a series of north – south oriented sandbanks emerge along the foreshore of Dutch beaches. Their interstitial fauna provides food for several shore bird species. Between these sandbanks (also known in literature as bars or ridges), shallow troughs exist (Dingler 2005; Chrastowski, 2005). These are drained at low tide and inundated at high tide, in accordance with the diurnal tidal cycle that prevails along this part of the European sea shore.

Only very occasionally, short winter conditions may freeze the surfaces of these sandbanks, also generating the formation of small pieces of sea ice (Figure 1). The last time that these conditions prevailed was January 2013.

Our observation of water escape structures

In 2013, January 25, some interesting water escape structures were observed near the coastal resort of Bergen aan Zee, (52o39’43’’ N, 4o37’59’’ E), in the Netherlands. At that time, winter conditions prevailed with a mean temperature along the North Sea coast of – 4,5o C (23,9 F). This was the last day with freezing conditions after the uninterrupted cold period, which started on January 13.

While the surface of the sandbanks was frozen into a hard upper layer, we observed on the lee side of one of the sandbanks, at low tide, about seven boiler plate or sieve plate alike structures on a row. Four of them performed the appearance demonstrated in Figures 2 – 5. Two of them were interpreted as an initial phase; we called them ‘blisters’ (Figure 6 – 7). The last of seven was destroyed because we were interested whether there were any burrowing animal species hiding in it, if there were other structures like a cavity, or streaming patterns to be observed inside. Neither an animal species nor any other structure were observed inside. We suggest that this could have been caused by the liquefaction of the water-saturated fine sand, thus preventing the formation of any permanent or semi permanent structure inside.

A literature search (see references) revealed that our structures were sand volcanos. The mean diameter of the observed sand volcanos (n=7) was about 30 cm and they were elevated between 2 and 4 cm. The direct surroundings of any sand volcanos were not frozen, however the wider adjacent area was frozen, as clearly shown in Figure 2 – 5. We did not record the thickness of this frozen layer. All sand volcanos had recently discharged water into the lower tidal basin: none of them were frozen and small volumes of water seeped out.

The hypothesized origin of these specific sand volcanos

Many but not all water escape structures along beaches will be caused by differences in height, thus creating differences in hydrostatic pressure. However, in our case there was ample difference in height, thus we questioned whether the hydrostatic pressure caused the observed sand volcanoes or not? Unfortunately, any experimental approach of this question was hardly possible.

Therefore we hypothesized that the rising tide created an increased hydrostatic pressure under the frozen upper layer of the sandbank as illustrated in Figure 8. Under normal conditions, without a frozen upper layer of the sandbank, the flooding water fills the interstitial space and discharges diffuse at the lee side of the sandbank into the trough. However, under these specific conditions observed and described here, the flooding water was not allowed to discharge in the normal diffuse way because of the frozen upper layer of the sandbank. The increasing pressure caused the water to discharge via weak spots on the lee side of the frozen surface, thus creating the row of observed sand volcanos. Figure 9 summarizes this hypothesis in situ.

In conclusion, the unique combination of local conditions most probably caused these sand volcanos. After these conditions changed with increasing temperatures, all sand volcanos disappeared. They were neither observed nor described before from the Dutch sandy coast.

Acknowledgements

I am indebted to Orrin Pilkey, William Neal, Joseph Kelly and Andrew Cooper for their critical questions and remarks on the hypothesis presented here. Thanks to the Coastal Care Team for publishing my submission for Beach of the Month.

References

  • BUIZER, BERT, 2018- Zandvulkanen op het strand bij Bergen aan Zee (accepted). Het Zeepaard 78(3).
  • CHRASTOWSKI, MICHAEL J., Beach Features. In: SCHWARTZ, MAURICE L. (ed.), 2005 – Encyclopedia of Coastal Science, 145-147. Springer, the Netherlands.
  • DINGLER, JOHN R. – Beach Processes. In: SCHWARTZ, MAURICE L. (ed.), 2005 – Encyclopedia of Coastal Science, 161-167. Springer, the Netherlands.
  • DOEGLAS, D.J. et al., 1973. Algemene Geologie. Zutphen.
  • GOOGLE and SCHOLAR.GOOGLE, lemmae: sand volcano / pictures; consulted 27-3-2018.
  • NEUMANN-MAHLKAU, PETER, 1976. Recent sand volcanoes in the sand of a dike under construction. Sedimentology 23 (3).
  • PILKEY, ORRIN H., WILLIAM J.NEAL, JOSEPH T. KELLEY & J.ANDREW G.COOPER, 2011. The World’s
    Beaches. Univ. of California Press, Berkeley.
  • REID, C.M., N.K. THOMPSON, J.R.M. IRVINE & T.E. LAIRD, 2012. Sand volcanoes in the Avon
    Heathcote Estuary produced by the 2010-2011 Christchurch Earthquakes: implications for
    geological preservation and expression.
    New Zealand Journal of Geology and Geophysics. Vol. 55, No. 3, September 2012, 249-254.

Te Pito O Te Henua shore (Rapa Nui or Easter Island): a remote and mysterious place with rare beaches; By Nelson Rangel-Buitrago, William J. Neal & Adriana Gracia

Nelson Rangel-Buitrago, Adriana Gracia, Grupo de Geología, Geofísica y Procesos Marino-Costeros, Universidad del Atlántico Barranquilla, Atlántico, Colombia, and William J. Neal Department of Geology, Grand Valley State University, Allendale, Michigan.

One of the most remote and youngest inhabited volcanic islands in the world is Te Pito o Te Henua Island, or as more commonly known: Easter Island (Rapa Nui or Isla de Pascua). World famous for its mysterious monumental statues (moai) erected by the early Rapa Nui people, the island is located in the southeastern Pacific Ocean nearly 3,650 km west of Chile; more than 2,000 km from the nearest inhabited land, being the southeastern most point of the Polynesian Triangle in Oceania and one of the most isolated places on the planet (Figure 1). This Chilean island of 164 km2 is part of the administrative Valparaíso Region (V region) that also encompasses the island of Isla Salas y Gomez, located 385 km to the east. The island shares with the Juan Fernandez Islands the constitutional status of “special territory” of Chile. In 1995, UNESCO named Easter Island a World Heritage Site, and much of the island is protected within the Rapa Nui National Park (45% of the island).

Most travelers to the island are drawn there by the mystery of the large statues and associated archaeology of the lost culture that produced these monuments (Figure 2), and a later “birdman” culture. Numerous authors have treated these subjects, including presentations of this lost, isolated society as an example of humans contributing to the collapse of the very ecosystem on which they relied for existence.
The Polynesian discoverers/colonizers of the island found a tropical paradise, abundant vegetation, fish, shellfish, birds, and palm forests that provided lumber for their canoes as well as cloth and rope. The forest provided cover for shade crops, water retention, and a deterrent to soil erosion.

“The island’s volcanic origin has generated kilometers of amazing rocky coastline, dominated by erosional features. ”
— N.Rangel-Buitrago, A. Gracia & W. Neal

It’s a reasonable assumption that as the moai construction grew, and statues were moved to other parts of the island, that logs and polls were used to move these massive monuments. The resulting deforestation then led to a cascading effect of loss of boat-building materials (limiting fish harvest), crop losses, loss of ground cover, increased soil erosion, and a decline in the bird population. Some contend that part of this collapse was also due to climate change from the Little Ice Age. Evidence points to a resulting social breakdown, conflict, and starvation. Then the arrival of slavers from South America and the introduction of western diseases contributed to the final population decline.

The focus here, however, is on the island’s shoreline which begins with the geology. The island’s location is the result of the coalescence of three shield volcanoes that erupted between about 770,000 and 100,000 years ago (Rano Kau, Poike, and Terevaka) at the boundary of the Easter Microplate and the Nazca Plate, and are part of the Easter Sea Mount Chain. These volcanoes formed over a hot spot and grew from the seafloor to emergence. The rocks of the island have been mapped as seven distinct volcanic groups, reflected in different rock types, landforms, and associated events. Basalt and hawaiite (olive basalt) lava flows are the dominant rock types. Rano Raraku, a volcanic crater and site of the moai quarry, and Ranu Kau, a crest caldera (Figure 3), are large volcanic features. A few small cinder cones reflect some younger eruptions.


Figure 3. Rano Kau Volcano in the SW arm of the island is marked by a summit caldera that holds one of the islands few fresh-water lakes and wetland.

Sea Cliffs and Beaches

The island’s volcanic origin has generated kilometers of amazing rocky coastline, dominated by erosional features. Sea cliffs ranging from a few meters in height to those that reach 300 m are most extensive (Figures 4 and 5). Small islets (Motu-Nui, Motu-Iti, and Motu-Kaokao located in the southwest) and sea stacks are erosional remnants of the former coast (Figure 6). Erosional shore platforms now make up some of the relative flat land areas bordering the shore (Figures 7 and 8). Caves in these coastal cliffs abound, but rather than being true sea caves, many are exposed lava tubes, and consist of hidden rooms joined by narrow tunnels that often extend far into the lava beds (Figures 9 and 10).

Important:

Cliffed areas in general are dangerous, whether at the edge or the base. Tunnels pose hazards of their own. Always use extreme caution with respect to extreme waves, rock falls and cliff edge/face collapses. In a similar vein, some places are sacred to the Rapa Nui Community, and passage is restricted. Refer to the Park rules and warnings before your visit. Also, collecting rocks, sand, biota, is not allowed.

The volcanic rocks are resistant, but fine-grained and lacking sand-sized or coarser particles of resistant minerals that form sandy beaches. So boulders dominate what we think of as the ‘beach zone’ (Figure 4), and green or black sand beaches like those in Hawai’i are absent. There is some growth of reef-associated organisms that provide carbonate skeletal sand-sized material for the island’s very scarce sand beaches. These occur as pocket beaches in wave-eroded embayments, washed by shallow turquoise waters. Only three sandy beaches can be found on the island: Anakena Beach and Ovahe Beach, both located on the north side, and Pea Beach, in Hanga Roa. Pea Beach is of such small size that it’s of little note here.


Figure 11. Anakena Beach is a beautiful pocket beach of carbonate sand. Two archaeologic features, Ahu Ature Huki (the lone moai statue in background), and the Ahu Nau Nau (seven moai on right), add to the mystic of beach. The stones mark off the ‘sacred area’ around the monuments.

Anakena Beach:

If you are looking for a world-class ‘perfect’ beach this is the place (Figure 11). The pocket beach is located in a short embayment, and is composed of white and delicate coral sand washed by crystalline turquoise waters, and surrounded by coconut palms imported from Tahiti (Figure 12). The pattern of inland sand transport, a barren flat, and small dune features, give evidence of occasional strong onshore winds. In addition to being an idyllic beach, this is the cradle of origin for the Rapa Nui people. According to legend, their history began in this place with the arrival of the first king of the island, Ariki Hotu Matu’a. At the back of the beach are two ceremonial platforms, the Ahu Ature Huki (a single moai statue, first to be raised on the island in modern times), and the Ahu Nau Nau (a platform composed by seven moai, Figure 11). The beach is flanked by two cinder cones to the East which are part of a headland, separating it from Ovahe Beach.

Ovahe Beach:

This smaller pocket beach to the east of Anakena, across the wide volcanic headland (with the two cinder cones) is of similar sand composition, but stands in contrast in that it is ringed in by a semicircle of sea cliffs. The cliffs result in more difficult access to the beach, and are a hazard in terms of falling rocks. A line of boulders crossing the beach should suggest to the beach goer to be wary of possible falling rocks.

Biota

This isolated island’s climate is typical of a tropical rainforest, but sometimes changing to a humid subtropical climate due to rains that average 1,100 mm per year. The geographic location allows winds to keep temperatures between a 15 C° avg. in July-August (coldest season) to 29°C in February (summer season). Because the island is near the South Pacific High and outside the range of the intertropical convergence zone, cyclones and hurricanes do not occur, but rainstorms and heavy rainfall occasionally strike the island.

Botanical studies define the Eastern Island as a paleo-subtropical broadleaf forest. The above classification is because fossil records of tree molds (in lava flows), fossil pollen, and root casts found along with the soils, indicate that in the past the entire island was formerly forested with a range of trees, ferns, shrubs, and grasses. For example, the Paschalococos disperta, an extinct palm, was one of the dominant trees as attested by fossil evidence. Upon the European arrival to the island, the endemic toromiro tree was the only wild tree, and the Carolina wolfberry the lone native shrub; the vegetation being predominantly herbaceous. Island wood carvers overexploited the toromiro tree, and the last local specimen died in the 1950s. Today 31 wild flowering plants, 14 ferns, and 14 mosses are reported. Grass and small ferns dominate the volcanic landscape, whereas lakes are thickly covered by two imported American species, the totora reed and Polygonum acuminatum (a medicinal plant). Currently, trees are sparse, rarely forming natural groves, and, as noted above, it has been argued that local Easter Islanders deforested the island in the process of erecting moai, and in providing sustenance for an overpopulated island.

In the past, island animal life was restricted to a very few species of isopods, spiders, insects, worms, and snails. Rats probably arrived with the pioneer Polynesians, and later could have contributed to the collapse of the ecosystem. Sheep, horses, cattle, and pigs were introduced by colonies of missionaries who established themselves on the island in 1865, and remain the dominant animals today.

Marine life of the clear turquoise waters is dominated by crayfish, sea turtles and various coastal fishes that abound around the entire coast, and are popular with divers and snorkelers. All of these features provide for activities that include beachcombing, snorkeling, diving, and surfing; a perfect place to commune with Nature.

The Travel Ideal?

Easter Island has to rank high on anyone’s travel ‘bucket list’ simply for the amazing archaeology. But the palate of beauty, both landward and seaward of the shore, makes Te Pito o Te Henua Island an experience unique in the world. Anakena Beach, as small as it is, ranks in the top 10 on our list. All across the island, hiking trails provide access to breathing fresh air, exploring Nature’s wonders of volcanoes and rocky shores, and visiting the amazing archeological wonders of the Rapa Nui people. And remoteness and lack of high-rise tourism favors night-sky watchers.

Water enthusiasts will find opportunities for surfing, and the island is a perfect place for diving activities because the waters are clear and transparent (visibility can reach up to 70 meters), with temperatures of 18 to 26 C°, that make the diving experience unforgettable. (Note: Dive and see the moai on the ocean bottom in Hanga Roa Bay for a wonderful experience).

Nine coastal sites to visit around the island

  1. Rano Kau Volcano and the Orongo Village:
  2. The Rano Kau is a 330 m high, extinct volcano that forms the southwestern headland of the Easter Island. The Crater Lake is one of the island’s only three natural bodies of fresh water (Figure 3). The ceremonial village of Orongo is located at the point where the inner crater wall converges with the sea cliff (Figure 13). In the past, Orongo was the center of a birdman cult whose defining ritual was an annual race to bring the first manutara (sooty tern) egg back undamaged from the nearby stack of Motu Nui to Orongo (Figure 6).

  3. Ana Kai:
  4. This coastal site is located just south of Hanga Roa (the town), not far from the road to Ranu Kau volcano. Ana Kai or “the cave of the cannibals” is on a terrific coastal landscape composed of black cliffs, and the cave is decorated with Rapa Nui paintings (Figure 9). Currently, the cave entrance is closed due to falling rocks. However, the coastal scenery is stunning.

    “Anakena Beach is a beautiful pocket beach of carbonate sand. Two archaeologic features, Ahu Ature Huki (the lone moai statue in background), and the Ahu Nau Nau (seven moai on right), add to the mystic of beach… ”
    — N.Rangel-Buitrago, A. Gracia & W. Neal

  5. Hanga Piko:
  6. This may be one of the most exotic harbors in the world. Hanga Piko means “Hidden Bay,” and inside this port is a ceremonial complex consisting of the Ahu Ataranga, the Ahu Ana Hoto Huero and the Ahu Riata platforms (Figure 14). Due to its excellent access to the sea and its anchorage conditions, this area is the most prominent harbor of the entire island and gives shelter to different marine activities.

  7. Tahai:
  8. This ceremonial complex is said to be one of the best places in the world to watch the sunset. The compound comprises three principal ahu: Ko Te Riku, Tahai, and Vai Ure (Figure 7). The tomb of William Mulloy, the famous anthropologist who came to the island with the Thor Heyerdahl expedition in 1955, is located in the south of this complex.

  9. Hanga Kioe:
  10. This site consists of a coastal esplanade with two moais: the Ahu Akapu and the Ahu Hanga Kio’e. Inside this complex is a square, a hare moa (chicken coop), and also several remains of hare paenga (boathouses), which were part of the ceremonial center (Figure 8). Hanga Kioe means “Bay of the Mouse.” This name comes from an old Rapa Nui legend about a widow who entered this place with a mouse in her mouth, in mourning for the death of her husband, whose remains were buried here after the ceremonial platform was built.

  11. Ana Kakenga:
  12. Ana Kakenga, or the cave of the two windows, is perhaps the most beautiful cave on the island. This volcanic tube, about 50 meters long, was used as a refuge cave during the struggles that took place between the different clans of the island. If you aren’t claustrophobic, the only available access can be found camouflaged in the grounds; a small hole, slightly more than half a meter wide. A short walk in the cave leads to two natural windows, situated 30 meters high on the face of the volcanic cliff where the lava tube exited towards the sea. These windows provide a terrific view of the nearby islets, called Motu Ko Hepoko and Motu Tautara (Figure 10). For non-cavers, this fantastic scenery can be seen from along the face of the sea cliff (Figure 4).

  13. Ahu Te Peu:
  14. Ahu Te Peu is the gate to the island’s untamed northern coast. This separate cliffed area remains almost untouched since it is less visited by tourists. The megalithic complex has several fallen moai and a village site with foundations of hare paenga (elliptical houses), and the walls of several round dwellings consisting of loosely piled stones (Figure 5). Here you can feel the isolation of the island from the world, and breathe clean air while listing to the waves crashing on the cliffs. Ahu Te Peu is among the most peaceful places in the world.

  15. Anakena:
  16. Similarly, Anakena Beach is a peaceful place and, as noted above, a world class beach (Figures 11 and 12). Offshore reef organisms are the source for the sand-sized fragments of coralline and other calcium-carbonate skeletal material that makes up the beach. The archaeologic sites, cinder cones, nearby Ovahe Beach, and rocky-shore features all add to the attraction of this site.

  17. Ahu Tongariki:
  18. In fact, most of the sites noted here have multiple attractions, and this is again true for Ahu Tongariki. The combination of the Rano Ranaku Volcano, sea cliffs, stacks, turquoise water, and 15 impressive moai statues is more than unique, and it’s difficult to find sufficient adjectives to describe the beauty of this coastal site (Figure 2). This place was the sociopolitical and religious center of the Hotu Iti, one of the two great clans that grouped the tribes of the eastern sector of the island. This family left, as a legacy, one of most massive ceremonial structures built on the island and the most important megalithic monument in all of the Polynesia region. The times of the “summer solstice” (December 21st) and “autumn equinox” (March 21st) are ideal for observing the sunrise in this place, when the sun-rise through the back of the moai gives a spectacular, unforgettable image.

Trouble in Paradise

Not all is perfect in Eden! Once again the island is threatened by population growth. Significant numbers of tourists, plus immigrants from mainland Chile, and reliance on a tourism economy that encourages more development and heavier use of infrastructure are straining the island’s resource management, including adequate safe water supply and waste processing facilities. In particular, Litter is a big issue for the island. These critical problems currently are threatening all world coastal environments, but are more obvious in island environments. Unfortunately, Easter Island is no exception as 20 tons of litter are produced daily. As an indication of the scale of the solid-waste problem, the recycling plant, that opened 17 years ago, processes at least 41,000 plastic bottles every month. In the same way, the island is an example of how humans can impact an area without even being there. Significant amounts of refuse, especially plastics and microplastics, arrive every day on this beautiful coast (Figure 15).

Te Pito o Te Henua Island is undoubtedly one of the wonders of the world. The people, the scenery, and the stunning moai, standing on their stone plinths are unique. But it is clear, this island has issues to solve. If these problems are unaddressed, they could eventually damage the present and future of one of the most singular places on the planet. This island’s ecosystem and population crashed in the past – its history provides both a lesson and a warning.


Additional reading

Newfoundland’s Sandy Beaches: A Glacial Legacy; By William J. Neal & Joseph T. Kelley

By William J. Neal, Dept. of Geology, Grand Valley State University, Allendale, MI, and Joseph T. Kelley, School of Earth and Climate Sciences, University of Maine, Orono, ME.

“Newfoundland” as a coastal place does not conjure up images of sandy beaches, but rather scenes of wave-cut rocky cliffs, bird rookeries on small rock islands, sea stacks, and boulder and cobble beaches if wave deposits are present. But scattered among the latter are genuine sand beaches – sometimes in association with gravel deposits, but where sizes are distinctly sorted by variable wave energies from strong storms to the quieter times of gentle waves. Beach types range from a few long reaches and shorter arcuate strands where greater sand supplies are available, to pocket beaches in protected coves of lower wave energy.

Although not all inclusive, Figure 1 shows the distribution of the beaches mentioned here. Geologically, Newfoundland is an extension of the Appalachian Mountains with a geologic history that produced a wide range of igneous, metamorphic, and sedimentary rocks, ranging in age from Precambrian through Paleozoic, in three distinct structural zones. These three SW-NE trending zones are reflected in the island’s geography, and controlled the land’s response to the much more recent glacial erosion during the Pleistocene. The direction of ice movement either paralleled the structural trends, or flowed off of the highlands, and had much to do with the great irregularity of Newfoundland’s coast – over 17,500 km in length. The glaciers originally produced most of the sediment found on today’s beaches – from sand to cobbles- by grinding up rocks they passed across. Old glacial outwash deposits such as deltas, the coarser fractions of tills, and raised beach ridges are often the immediate sediment sources for the modern beaches, brought to the shore by rivers, or directly eroded by waves.

The Western Zone includes the great north-trending arm of the Long Range Mountains, where glaciers during many glaciations stretching back more than a million years carved deep fjords from E to W into the sea. The variety of rock types seen in the cobble and gravel beaches, as at Green Point and Martin’s Point, is a reflection of varied geology back in the source area (Figures 2 and 3). The composition of sandy beaches and dunes vary similarly. Port au Port, at the south end of the western arm, is a huge double tombolo (two sand beach bars that connected the mainland to what was once an island, forming the Port au Port Peninsula). The light-colored beach sand is derived from an eroding high-stand delta (with an endangered cemetery on top) (Figure 4A). Similar sand-rich deposits in the area were the sediment sources for Flat Island, a classic spit on the SW coast (Figures 4B&C). In contrast the poorly-sorted beach sand at Trout River on the south edge of Gros Morne National Park is dark in color because of an abundance of sand and granule-sized rock fragments (Figure 5).

“The glaciers originally produced most of the sediment found on today’s beaches… ”
— W. Neal & J. Kelley

The main road north (highway 430) along the western arm provides access to various interesting sites – a few small beaches, often near stream mouths (Figure 6A) and with associated dune fields, such as Shallow Bay beach (Figure 6B) near Daniel’s Harbor, and the Three Arches (Figure 7), a popular spot for viewing erosional features. These arches and elevated beaches at localities such as Port au Choix are evidence of glacial rebound, the post-glacial uplift after the mass of the glacier was removed. This western highway (430) is the access route to Port au Choix and L’Anse au Meadows (Viking settlement), and there is still evidence of where beaches and dunes were mined away, probably in the late 1950s and early 1960s to build the road, completed in 1962 (Figure 8).

The island’s Central Zone has a highly crenulated northern coast, while its southern coast line is cut by numerous narrow fjord-like embayments. We visited no beach locales in this section because there is no road along the southern coast, and the highway is distant from the northern coast, but some of the coves are home to small pocket beaches.

The Eastern Zone also has good examples of such pocket beaches in coves. The Eastport Peninsula touts three beaches as tourist attractions. Sandy Cove, the most scenic, is a light-colored beach of sand derived from the erosion of a Pleistocene delta that forms the upland behind the beach. The bare-bluff face rises 75 feet above sea level. In nearby Eastport, the smaller public beach has convenient access and public facilities (Figure 9) with some interesting beach features including multiple wrack lines, cusps (Figure 10), and erosional features associated with a creek mouth (Figure 11). Nearby is Northside Beach, a longer reach with a higher gravel component, and evidence of multiple higher stands of water level (Figure 12).

One of the most interesting Eastern Zone beaches is at Elliston on the Bonavista Peninsula. Concentrations of dark-colored heavy minerals were not common in most of the beaches we visited, however, Elliston Beach had an abundance of heavy minerals resulting in a greater visibility of some common beach structures (Figures 13 – 16). Like other Newfoundland beaches, Elliston’s is also water saturated as opposed to beaches that commonly have air-filled holes at low-tide which may explain why no air holes, blisters, or ring structures were seen. And Elliston is the root cellar capital of the world!

Like the rest of Newfoundland, gravel beaches are more common in the Avalon area than sand beaches, but Salmon Cove sands is one of the exceptions (Figure 17). Once again we see that the beach owes its origin to the ready source of glacially-derived sediment, delivered by a river into the head of an embayment. The beach is wide enough to have a dry back-beach area of sand that the wind works on to produce sand dunes, and, on a finer scale, adhesion structures when dry wind-blown sand sticks to the wet-sand surface of the beach (Figure 18). The Placentia area also has mixed gravel and sand beaches, as well as old beach ridges inland that mark former shorelines (Figure 19). To develop a beach-ridge plain requires a large source of sand and gravel that is released and accumulates episodically during storms. It is unfortunate that this area was developed by the government to re-settle people from remote villages and erosion is held at bay by a large seawall.

If scenery is what you search, the coarser beaches of Avalon have plenty to offer. Chance Cove Provincial Park is a good example of a panoramic view area where there is not only a scenic beach (Figure 20), but also the opportunity for spotting whales, sea birds and ice bergs. The coarse pebble beach at St. Vincent’s may not have the pebble variety you seek, but a walk in the gravel is well worth the experience of seeing a whale breach in the nearshore. Whether sand or gravel, every beach is different, each with its own surprises, like finding a wrack line that looks like it could lead to a sardine factory (Figure 21)! Newfoundland’s beaches are no exception – even when the waters are too cold for swimming, these beaches are a combers’ delight.

Torrevieja, Spain; By Norma J. Longo

By Norma J. Longo, Nicholas School of the Environment, Duke University, Durham, North Carolina.

Torrevieja, a former fishing village on the southeast coast of Spain (Costa Blanca) in Alicante province, is now a thriving tourist city with a 2016 population of around 85,000, down from a high of over 105,000 in 2013. The projected population for 2017 is 92,752, a number that likely expands to about half a million in high season (1). With an advertised 320 days of sunshine a year,(2) the entire 200 km coastline of the Costa Blanca region along the Mediterranean has a busy tourist industry. Temperatures are normally mild for most of the year, with warm winters, but on January 18, 2017, Torrevieja had its first snow in over a century (3). Winter storms over the last three years have brought high winds and waves up to 6 meters, eroding beach sands and damaging homes. An Alicantetoday.com news article mentions that the national government spent almost 4.7 million euros to repair last winter’s storm damage on the beaches of this province. The northernmost beach of the city of Torrevieja, Playa de la Mata, had a 260-meter-long wooden seafront promenade. In an attempt to prevent further beach erosion, the decision was made to remove the promenade and replace it with a concrete retaining wall that was completed by June 22, 2017, at a cost of €650,000. According to the news article, the beach has effectively been made 4 meters wider, with 1,000m2 of “extra” beach as a side effect of the seawall (4). However, seawalls are not normally considered to be beneficial for a beach, as they are built to protect buildings or property, not beaches. The detrimental effects of seawalls have been known for decades and seen on other beaches worldwide. Scientists Pilkey and Wright (1988) noted that seawalls effectively destroy beaches along eroding shorelines (5).

Torrevieja has a series of golden, fine-to-medium-grained sand beaches (five of which are Blue Flag rated, i.e., good water quality, clean, accessible, etc.), along with some rocky stretches made up of carbonate beach rock associated with former coastlines (6,7). Most of Torrevieja’s beaches have lifeguard and first aid stations and some also have space for volleyball courts and children’s play areas. This Mediterranean locale is ideal for sunbathing and swimming, and in some places along the Torrevieja shore, buoys demarcate the safer swimming areas. While the largest known tidal range here is 0.17 meter (8), one area alongside the Paseo Juan Aparicio has man-made containment areas for sand and safe swimming pools that are connected to the sea. Breakwaters and jetties surrounding these areas protect against large waves and are used by both fishermen and sunbathers. Rock pools entertain children who enjoy exploring them for marine life.

“With an advertised 320 days of sunshine a year, the entire 200 km coastline of the Costa Blanca region along the Mediterranean has a busy tourist industry… ”
—Norma J. Longo

The individual beaches of Torrevieja are separated by a harbor, rock jetties, coves, and creeks. From SW to NE are Playa de los Naufragos and Playa del Acequion, sandy beaches that lie on either side of the salt conveyor belt described below; the rocky Paseo Maritimo Juan Aparicio with its protected swimming areas and decking over some of the rocks; Playa del Cura, a busy, central, urban beach that is bounded on the north by a rock jetty; Cala del Palangre, a small cove beach, one of many coves along the coast; Playa de los Locos, a long sandy beach that also has some exposed rocky areas; Calas de Torrevieja, a long stretch of coves in the beachrock coast; and finally, Playa de la Mata. A rocky point, Cabo Cervera, lies south of Playa de la Mata.

Playa de la Mata is the biggest, over 2 km long and 40 meters wide, although of variable width, with considerable beachfront development such as restaurants, homes, and shops. La Mata ends on the north at the Canal de las Salinas that divides it from the beaches of the next northerly town, Guardamar del Segura. Guardamar’s beaches were also damaged in the 2017 winter storms, leaving some beachfront properties in need of repair (9). In mid-town Torrevieja, Playa del Cura is a popular 325-meter-long crescent-shaped beach. The promenade has wooden benches where you can sit and listen to the sounds of the sea. Playa de los Locos (named after a former psychiatric hospital nearby) is 760 meters long and 25 meters wide (10). This beach lies just north of a rock jetty and is bordered to the north by a rocky point with buildings, including an apartment complex.

Large amounts of seaweed are common in several areas, but the sandy beaches are cleaned daily by machines, which makes for neatly groomed beach sands but which has been shown by scientists to harm the beach fauna. Torrevieja’s beaches are not dog-friendly, but in 2016, the city of Santa Pola farther north along the coast opened a dog beach, La Caleta dels Gossets, at a protected cove. Since beach sands can sometimes be polluted by human or animal waste, the city has strict rules in place to keep this special beach clean (11). In the short time since its designation as a dog beach, it has become a popular destination, with no seawalls in sight.

Much of the Torrevieja shoreline is protected by seawalls, with some local businesses (such as restaurants) jutting out onto the beaches in places. Several buildings along the Acequion beach north of the port of Torrevieja are on the sand and very close to the water line. Seawalls along most of the beaches are backed with a palm-tree-lined promenade that stays busy—people strolling, sitting on benches, eating and drinking at the many restaurants, kiosks, and shops, and enjoying the breeze, although it can be choked with cigarette smoke. As of May 2017, the city council, after receiving numerous complaints of there being too many cigarette butts in the beach sands, opted to distribute portable ashtrays for smokers to use and dispose of in available wastebaskets (12). Beyond the seawalls, concrete benches are scattered around on top of the rocky lengths of beach, and a few ladders lead down into the sea. One of the benches “hosts” La Bella Lola, a lady in bronze who gazes out toward the horizon, awaiting the return of her husband who was lost at sea. She is said to symbolize all of the women who have watched their men sail away never to return again (13).

Torrevieja is situated in a region that is associated with several fault lines. The NW-SE dextral Torrevieja Fault, part of the Bajo Segura fault zone, is known to be active, and the entire coast is earthquake prone. The convergence of the African and Eurasian tectonic plates, currently at about 4 to 5 mm/year, creates seismic activity that consists mostly of low-magnitude quakes or tremors which are often ignored by people (14). However, one quake in the past was devastating. The March 21, 1829 earthquake that registered 6.6 on the Richter scale killed 389 people in and around Torrevieja and leveled the entire village, plus it caused widespread property damage up and down the coast (15). A 3.6 magnitude quake struck in March 2008, a number of others occurred between 2011 and 2015, and on March 9, 2017, parts of the city of Torrevieja were shaken, although without injuries or destruction (16). Since underwater earthquakes can potentially trigger tsunamis, this area will be vulnerable to inundation.

Despite the seismic activity, this part of Spain is known for attracting tourists and expats. Torrevieja is a large, sprawling city dominated by foreigners, although a number of Spanish tourists and residents also visit or reside here. Many British, German, and Scandinavian expats own second homes or apartments in the city or in other towns around Alicante. Along the coast to the northeast is Benidorm, another former fishing village that is now filled predominantly with high-rises, built in a relatively confined space due to the large cliffs that border on the city. Benidorm, like Torrevieja, is popular with tourists and also is populated with expats from several countries. The beaches of Benidorm are beautiful and usually crowded, as are those of Guardamar del Segura and Santa Pola. Away to the south lies La Manga, a sandy barrier that separates the Mediterranean from Mar Menor, the largest lagoon on Spain’s Mediterranean coast. The barrier is about 20 km long and ranges from 30 to 500 meters in width but is less than 3 meters above sea level (17). Extreme storm events in the western Mediterranean may be rare, but this coast is vulnerable to flooding from storms and sea level rise. The barrier is densely developed and has numerous tall buildings, which will be difficult to eventually move back from the rising seas, as is the case in Benidorm.

“The huge tourist industry is due to the climate and the beaches, but the beaches are likely to be lost someday to the rising seas… ”
—Norma J. Longo

The 20-km coast of Torrevieja itself is not littered with high-rises, although it does have several. Many buildings here could be classed as low-rises, as they’re only about 6 to 8 floors high. The fishing industry is still thriving, and you’ll see a variety of fishing vessels and pleasure craft in the marinas. Torrevieja also has its famous salt lakes or lagoons which are below sea level and from which mountains of salt are shipped around the world. Connected to the sea by an artificial channel, the sea water infusion flows into the Lagoon de la Mata and is piped to Torrevieja lagoon where the salt is crystallized. Salt production has been increased by the use of salt from a diapir in the Cabezo de la Sal, Pinoso, where solution mining of halite via deep boreholes has taken place for many years. The brine from the boreholes is piped more than 60 km to the Torrevieja saltworks where the water is evaporated to yield the salt for distribution (18). A conveyor belt carries the salt to ships in the harbor.

Because of extraordinary amounts of rain during the winter of 2016 – 2017, the town had to import salt from Italy in May 2017 to meet the demands, as the lakes had become too diluted to efficiently yield enough of the commodity (19). Las Salinas de Torrevieja y La Mata are surrounded by a nature preserve that lends itself to a variety of unique flora and fauna, as well as recreational uses. The park is classified as a Zone of Special Protection for Birds (ZEPA zone) by the EU, is considered a Place of Community Interest (LIC), and is number 456 in the list of Ramsar Wetlands of International Importance (20,21). There is even a Sea and Salt Museum in Torrevieja (Museo del Mar y de Sal) that explains the history of the important salt industry in the area.

The huge tourist industry is due to the climate and the beaches, but the beaches are likely to be lost someday to the rising seas. Torrevieja and the other beach towns of Spain’s Costa Blanca will long remain magnets for sun seekers, earthquakes notwithstanding—and sea level rise may seem very distant or non-existent to them until their seawalls or rocky coastline no longer protect the buildings.


References:


Acknowledgments: Thanks to Andrew Cooper, Gina Longo, Bill Neal, and Orrin Pilkey for kindly reading and commenting.


Santa Pola Tourist Office

Torrevieja, Spain maps and Google: Torrevieja, Spain maps

Costa Blanca earthquakes

The rugged coast and black sand beaches of the Azores; By Gary Griggs

By Gary Griggs, Distinguished Professor of Earth and Planetary Sciences, Director Institute of Marine Sciences, University of California, Santa Cruz, California

A soft, white sandy beach on a lush green island is probably the vision many people have of their perfect coastal vacation. Eight hundred and fifty miles west of Portugal and 2400 miles east of Boston lies the lush island of São Miguel in the Azores. It is one of nine islands making up an archipelago spread across 300 miles of the North Atlantic Ocean.

The Azores are an autonomous region of Portugal and are a long way from anywhere. The islands are all volcanic in origin and first emerged from the sea about four million years ago. The Azores are in the midst of a tectonic junction where three different plates (the North American, European and African plates) come together, sometimes called a triple junction. This area is usually labeled as one of the planet’s hotspots, locations where hot thermal plumes emerge at the surface from deep within the Earth’s mantle. There are about 40 hotspots scattered across the Earth’s surface, Hawaii, Yellowstone, and Iceland being several well-known examples.

There doesn’t appear to complete geologic agreement on the origin of these volcanic islands, however. Rather than being a result of a hotspot, some believe that this volcanic archipelago is due to volcanism related to spreading along an ocean ridge that extends east from the Mid-Atlantic Ridge. This all matters little to the Azoreans, however, who have had to contend with intermittent volcanic eruptions and their associated earthquakes since they first occupied the islands about 500 years ago. Over the past 3,000 or so years, major eruptions have occurred on average about every 360 years. A major 13-month long eruption of Capelinhos on the island of Faial that began in 1957 led to the immigration of more than 4000 residents to the United States.

“Most of São Miguel’s coastline is very steep and rugged by virtue of its volcanic underpinnings. There are beaches scattered around the island’s shoreline, almost all consist of black sand from the weathering and breakdown of the island’s basaltic foundation… ”
— Gary Griggs

It is rumored that there are as many Azoreans living in the United States as living on the nine islands, which have a total population of about 245,000 with just over half living on São Miguel, the largest island. Whales and other marine mammals have always been common in Azorean waters and many men on the island became whalers back in the 1800s. With somewhat limited economic opportunities, signing onto a whaling ship from New England was often a ticket off the islands. As a result, many Azoreans ended up setting in places like New Bedford, Massachusetts, as well as California, where in the mid- to late-1800s, the great majority of the whalers working the 17 whaling stations spread between Crescent City and San Diego were from the Azores.

São Miguel is a remarkable and beautiful island, all volcanic and all very, very green from the combination of fertile volcanic soils and regular rainfall. There are a number of picturesque lakes filling ancient calderas, as well as boiling hot springs and bubbling mud pots. Holstein dairy cows seem to occupy most of the hilly landscape, kept in by old stonewalls, and looking very content. Road cuts and coastal cliffs reveal the evidence of the island’s eruptive history with ancient lava flows and layered volcanic ash deposits.

The Azoreans take remarkable care of São Miguel; trash seems to be almost non-existent, roads are well maintained and are lined by pink azaleas and millions of blue hydrangeas. Roadside vegetation everywhere is constantly trimmed and pruned. People are friendly, and food is good and inexpensive. Most of the buildings are of characteristic Mediterranean architecture, white plastered walls with red tile roofs. From the perspective of a 9-day stay, it seems pretty close to paradise.

Most of São Miguel’s coastline is very steep and rugged by virtue of its volcanic underpinnings. There are beaches scattered around the island’s shoreline, however, many at the mouths of small coastal streams where sediment has been delivered to the coast. They almost all consist of black sand from the weathering and breakdown of the island’s basaltic foundation, although there are a few that are more reddish in color from the weathering of the iron in the volcanic rock. Like beaches everywhere, they are popular in the warmer months and the black sand is no deterrent to their use and enjoyment.