Tag Archives: Coastal Issues

What was natural in the coastal oceans?

wild-horses-atlantic-coast
Wild horses at the beach, Cumberland island. Photo source: ©© Linda N.

Abstract, By Jeremy B. C. Jackson © 2001, The National Academy of Sciences

Humans transformed Western Atlantic coastal marine ecosystems before modern ecological investigations began.

Paleoecological, archeological, and historical reconstructions demonstrate incredible losses of large vertebrates and oysters from the entire Atlantic coast. Untold millions of large fishes, sharks, sea turtles, and manatees were removed from the Caribbean in the 17th to 19th centuries.

Historical reconstructions provide a new scientific framework for manipulative experiments at the ecosystem scale to explore the feasibility and benefits of protection of our living coastal resources…

Read Full Article, National Academy of Sciences

Sediment In Motion

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Sediment in Motion at Ocean City.

By Heather Hyre, NASA Earth Observatory

If you’ve ever stood in the water on an ocean beach, you’ve likely noticed a pattern in the way water and sand move across your feet. The direction oscillates between moving towards you (sometimes at an angle) carrying sand across the tops of your feet, and then away from you, removing sand from behind your heels and carrying it back out to sea. Your feet slowly begin to sink into the sand. Your feet are taking part in a micro version of a grand coastal process known as longshore transport.

Waves are generally steered ashore by the prevailing winds, often blowing at oblique (slanted) angles to the shoreline. Once a wave breaks, a shallow layer of water glides along the shore, carrying sediment with it. As the momentum from the wave deteriorates, gravity pulls the water downhill and back into the ocean—at least until the next wave moves in and carries the next load of sediment.

This process of longshore transport is responsible for moving sediment up and down coastlines. It can sometimes lead to the development of barrier islands and spits—thin strips of beach that generally form parallel to the mainland.

Before 1933, a single barrier stretched along the eastern seaboard of the Delmarva Peninsula in the United States. A major hurricane breached that barrier in August 1933 causing it to split into two islands: Fenwick Island to the north and Assateague Island to the south. The two islands are depicted in the image above, which was taken by an aerial survey plane on June 26, 2009. Various plumes of sediment are visible in the water both in the ocean and the bays.

Ocean City, Maryland—just north of the inlet—was already developing into a vacationer’s paradise before the barrier breach. After the split in 1933, the local fishing industry flourished, too, particularly after a decision to stabilize the inlet by building jetties on either side. Completed in 1935, the jetties were designed to allow easy navigation between the ocean and the bay.

The jetties, however, interrupted natural coastal processes such as longshore transport. The inlet choked off the continuous flow of sediment along the coast to the north end of Assateague Island, accelerating beach erosion. The effects of the Ocean City inlet were initially overlooked. But they are hard to ignore now that the north end of Assateague Island has migrated nearly 700 meters (2,300 feet) landward.

Growing concern about the rapid deterioration of Assateague Island led to the North End Restoration Project. The first phase, completed in 2002, replenished the beach with a one-time supply of 1.4 million cubic meters of sand. The second phase, started in 2004, is addressing the long-term effects of the jetties and attempting to re-establish a natural sediment supply to mirror pre-inlet rates.

With or without human intervention, coastal processes continually morph coasts into different shapes, sizes, and colors. Changes can be observed in a day, a season, or a decade, such that there will always be something different about the sand beneath our toes from one visit to the next.

Original Article, NASA

Slowing climate change by targeting gases other than carbon dioxide

bench ocean
Photo source: ©© Chodab

By NOAA

Carbon dioxide remains the undisputed king of recent climate change, but other greenhouse gases measurably contribute to the problem. A new study, conducted by NOAA scientists and published online today in Nature, shows that cutting emissions of those other gases could slow changes in climate that are expected in the future.

Discussions with colleagues around the time of the 2009 United Nations’ climate conference in Copenhagen inspired three NOAA scientists – Stephen Montzka, Ed Dlugokencky and James Butler of NOAA’s Earth System Research Laboratory in Boulder, Colo. – to review the sources of non-carbon dioxide (CO2) greenhouse gases and explore the potential climate benefits of cutting their emissions.

Like CO2, other greenhouse gases trap heat in Earth’s atmosphere. Some of these chemicals have shorter lifetimes than CO2 in the atmosphere. Therefore cutting emissions would quickly reduce their direct radiative forcing — a measure of warming influence.

“We know that recent climate change is primarily driven by carbon dioxide emitted during fossil-fuel combustion, and we know that this problem is going to be with us a long-time because carbon dioxide is so persistent in the atmosphere,” Montzka said. “But lowering emissions of greenhouse gases other than carbon dioxide could lead to some rapid changes for the better.”

Scientists know that stabilizing the warming effect of CO2 in the atmosphere would require a decrease of about 80 percent in human-caused CO2 emissions — in part because some of the carbon dioxide emitted today will remain in the atmosphere for thousands of years. In contrast, cutting all long-lived non-CO2 greenhouse gas emissions by 80 percent could diminish their climate warming effect substantially within a couple of decades. Cutting both CO2 and non-CO2 greenhouse gas emissions to this extent could result in a decrease in the total warming effect from these greenhouse gases this century, the new paper shows.

For the new analysis, the researchers considered methane; nitrous oxide; a group of chemicals regulated by an international treaty to protect Earth’s ozone layer; and a few other extremely long-lived greenhouse gases currently present at very low concentrations.

The new review paper describes the major human activities responsible for these emissions, and notes that steep cuts (such as 80 percent) would be difficult. Without substantial changes to human behavior, emissions of the non-CO2 greenhouse gases are expected to continue to increase.

The climate-related benefits of reductions in non-CO2 greenhouse gases have limits, Montzka and his colleagues showed. Even if all human-related, non-CO2 greenhouse gas emissions could be eliminated today, it would not be enough to stabilize the warming influence from all greenhouse gases over the next 40 years – unless CO2 emissions were also cut significantly.

The scientists also noted in the paper the complicated connections between climate and greenhouse gases, some of which are not yet fully understood. The non-CO2 gases studied have natural sources as well as human emissions, and climate change could amplify or dampen some of those natural processes, Dlugokencky said. Increasingly warm and dry conditions in the Arctic, for example, could thaw permafrost and increase the frequency of wildfires, both of which would send more methane and carbon dioxide into the atmosphere.

“The long-term necessity of cutting carbon dioxide emissions shouldn’t diminish the effectiveness of short-term action. This paper shows there are other opportunities to influence the trajectory of climate change,” Butler said. “Managing emissions of non-carbon dioxide gases is clearly an opportunity to make additional contributions.”

Original Article, NOAA

Ancient Tides Quite Different From Today

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High tide in the Bay of Fundy.

Tucked into a pocket between the Canadian provinces of New Brunswick and Nova Scotia, the Bay of Fundy is famous for having dramatic differences between its high and low tides. In fact, the tides observed here are tied with Ungava Bay (located farther north) for the largest tides on Earth. Under typical conditions, high tide at the head (the most inland part) of the Bay of Fundy is as much as 17 meters (about 56 feet) higher than low tide. Caption and photos source: NASA

ancient-tides-nasa
Low tide in the Bay of Fundy.

Excerpts; By The Oregon State University, in Science Daily

The ebb and flow of the ocean tides, generally thought to be one of the most predictable forces on Earth, are actually quite variable over long time periods, in ways that have not been adequately accounted for in most evaluations of prehistoric sea level changes.

Geological forces that act over hundreds to millions of years, such as plate tectonics, ice ages, land uplift, erosion and sedimentation, have caused the tides in certain places to vary wildly throughout history, according to a new study lead by David Hill, Oregon State University, and published in the Journal of Geophysical Research.

“Understanding the past will help us better predict tidal changes in the future,” David Hill said. “And there will be changes, even with modest sea level changes like one meter.”…

Read Original Article

Rare fossil of sea reptile found on Alaska beach

sea reptile
Thalattosaurs (meaning “ocean lizards”) are a group of prehistoric marine reptiles which lived during the mid-late Triassic Period. Some species of thalattosaur grew to over 4 meters (13 feet) in length, including a long, flattened tail used in underwater propulsion. Thalattosaur fossils have been found in California, Oregon, Nevada, and British Columbia. They are also present in Europe, with remains having been found from Switzerland, Austria, and Italy. More recently, thalattosaur fossils have been found in China. Wikipedia ©© Ghedoghedo / Wikimedia

Excerpts;

Alaska scientists have discovered the fossil of a rare, prehistoric marine reptile that is likely the most complete remnant of the creature ever found in North America.

The nearly complete fossilized skeleton, found during an extreme low tide along the shore of the Tongass National Forest, is of a thalattosaur, a long-tailed sea creature that plied warm, shallow waters in the early days of dinosaurs and became extinct at the end of the Triassic period some 200 million years ago…

Read Full Article, News Daily

Huge Ice Island Near Labrador ‘s Coast

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Huge ice island off Labrador’coast. Image source: NASA, Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC. Caption by Michael Carlowicz.

By Michael Carlowicz, NASA

Nearly 11 months after calving off of the northwestern coast of Greenland, a massive ice island is now caught up in ocean currents off the coast of Labrador, Canada.

The ice island, known as “Petermann Ice Island” was formed when a 251-square-kilometer (97-square-mile) chunk of ice broke off the Petermann Glacier on August 5, 2010. The Canadian Ice Service has since been tracking the ice island, dubbed PII-A, via satellite and radio beacon.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color image of the ice island on June 25, 2011. The northeast-facing coast of Labrador is mostly obscured by thin, wispy clouds, as it has been for much of the past week.

News agencies reported that the ice island stretched roughly 62 square kilometers in area and weighed between 3.5 and 4 billion tons.

The island has been slowly breaking up and melting on its journey—nearly 30 degrees of latitude, or more than 3,000 kilometers—but it could eventually pose a hazard to shipping lanes off Newfoundland.

Canadian fishermen captured this close-up video of the ice island.

WATCH: Ice Island Off labrador’s Coast, Close-up Video, “Petermann Ice Island video.”

Original Article

Huge ice island near Labrador ‘blew’ scientist’s mind
A huge island of ice the size of Manhattan is drifting off the coast of Labrador, and it’s a glacial event that has scientists around the world abuzz.”It blew my mind at how big it was,” said Sara Weikamp, a marine science technician with the U.S. Coast Guard.

Elwha River Restoration: Dams Removal Project

elwha dam
The Elwha Dam is a 108-ft (33 m) high dam located in the United States, in the state of Washington, on the Elwha River approximately 4.9 miles (7.9 km) upstream from the mouth of the river on the Strait of Juan de Fuca. Photo by Larry Ward, Lower Elwha Fisheries Office (2005).

Elwha River Restoration, Olympic National Park Washington

By The National Park Service, US Department of the Interior, Olympic National Park

This September, removal of two dams on the Elwha River begins, setting in motion one of the largest restoration projects in U.S. history.

Removing Elwha and Glines Canyon Dams
The largest dam removal in U.S. history will free the Elwha River after 100 years. Salmon populations will swell from 3,000 to more than 300,000 as all five species of Pacific salmon return to more than 70 miles of river and stream.

Renewing a Culture
The returning salmon and restored river will renew the culture of the Lower Elwha Klallam Tribe, who have lived along the river since time immemorial. Tribal members will have access to sacred sites now inundated and cultural traditions can be reborn. The NPS and the Tribe are primary partners on this project.

Restoring an Ecosystem
This project creates a living laboratory where people can watch and learn what happens when salmon return after a century to a still wild and protected ecosystem. The return of fish will bring bear, eagles and other animals back to an ecosystem that has been deprived of a vital food source for 100 years.

Economic Benefits
Just as the dams played a vital role in the history and development of the area, removing them will create new opportunities for growth and regional vitality.

Restoring the Coast
Removing the dams will reestablish the natural flow of sediment from the mountains to the coast—rebuilding wetlands, beaches and the estuary at the river’s mouth.

Elwha River Restoration
Olympic National Park Washington

Major mitigation projects have been completed, while preparations continue at the Elwha and Glines Canyon dams, the park’s native plant center, and sites throughout the Elwha watershed. Dam removal begins September 17.

June
• Power production ends at the Elwha River hydro- project June 1, and the U.S. Bureau of Reclamation begins the decommissioning process.
• Water levels in Lake Aldwell and Lake Mills drop by 18 feet and remain at this level through the summer. Boat launches will be unusable.

July
• On July 1, Lower Dam Road closes to public access as the Elwha Dam site transitions to a construction environment.

August
• On August 1, Olympic Hot Springs Road closes to public access just south of Altair Campground and will remain closed through dam removal.

• The second of two levees at the river’s mouth is completed in order to provide continued flood protection to private landowners and the Lower Elwha Klallam Tribe’s reservation.

September
• Wayfinding exhibits are installed at six Port Angeles and Elwha Valley locations, and a trail is constructed to an overlook at Elwha Dam. Web- cams go online from both dam sites.
• Elwha researchers and visiting scientists gather to share their findings at a science symposium Sept. 15-16 at Peninsula College.
• Olympic National Park and a diverse team of partners host a multi-venue event Sept. 17-18 featuring Elwha-related art, music, and cultural and educational activities.

For photos, project updates and news, check nps.gov/olym or interact with “Elwha River Restoration” on Facebook.

Elwha River Restoration, The National Park Service, US Department of the Interior

Olympic National Park


Elwha Dam Closed to Public Access : Effective July 5

By The National Park Service, US Department of the Interior, Olympic National Park

Lower Dam Road, which leads from U.S. Highway 112 to the Elwha Dam, will close to all public access on July 5.

Barnard Construction, Inc., the contractor for the $26.9 million removal of Elwha and Glines Canyon Dams, will install a gate just south of Elwha RV Park. This closure will last for the duration of dam removal, expected to take three years.

The closure is necessary to ensure public safety while the contractor takes over the site and begins preparing the site. Over the coming weeks, Barnard employees will begin minor road upgrades, removing approved trees and widening the road.

Additional work taking place this summer includes testing and removal of hazardous materials from the Elwha powerplant, including asbestos and lead-based paint. Major demolition work at the dam will begin in mid-September, with the majority of Barnard employees and equipment mobilizing in late August.

Barnard was the contractor for recently-completed road repairs at Fisherman’s Corner, along Olympic Hot Springs Road approximately one mile south of the park boundary. Those repairs included erosion control and replacing asphalt along a 2000-foot section of road. Work was subcontracted to Bruch and Bruch, Inc. and Lakeside Industries, both of Port Angeles, Wash. and performed as a modification to the dam removal contract.

Elwha Valley Access
Following a four-week closure, the Elwha Valley of Olympic National Park, including the Elwha and Altair campgrounds, reopened to public access June 29. The Elwha campground is open year-round. Altair will remain open through September 6, its normal operating season.

On August 1, Olympic Hot Springs Road will be gated and closed at a point just beyond Altair campground for the duration of dam removal.

Final designs for repairs to the Whiskey Bend Road are still being developed. These repairs will correct extensive damage caused by heavy rains last December. In addition to slide damage, an assessment by road engineers revealed large voids under the road, seriously compromising road safety and stability. The 4.5-mile Whiskey Bend Road remains open at this time to pedestrians, bicyclists and stock users, who should be use extra caution when crossing the damaged areas.

Olympic National Park is pursuing ways to enable members of the public to view dam removal and restoration as they happen, including construction of an overlook trail off of Lower Dam Road and placement of webcams at each dam site.

High-Elevation Park Roads
Olympic National Park road crews continue clearing snowdrifts that have delayed the opening of some of the park’s high-elevation roads. Obstruction Point Road, which was scheduled to open July 1, is blanketed by snow up to six feet high. After the plows reach the area commonly known as Waterhole (Milepost 3.2), the road crew will finish grading and that section of road could be reopened within one week.

Deer Park Road is also still under snow, with drifts several feet high at the top. Weather permitting, the road’s normal operating season runs May 26 – October 2. After the road crews reach the Waterhole area of Obstruction Point Road, their focus will shift to Deer Park Road. Park officials estimate that Deer Park Road may reopen by the end of July.

Road Construction
A 35-day road construction project is planned for Graves Creek Road this summer to repair damage caused by erosion along a 210-foot embankment adjacent to the Graves Creek trailhead and campground. Timing for this roadwork has yet to be finalized, and will be announced as soon as details become available.

Preliminary road repairs on Sol Duc Road will begin July 18. No closures are necessary for this project, but visitors should expect one-lane traffic and minor delays starting August 8 as contractors repair slide damage.