Over one-third of the world’s population already lives in areas struggling to keep up with the demand for fresh water. By 2025, that number will nearly double. Some countries have met the challenge by tapping into natural sources of fresh water, but as many examples, such as the much-depleted Jordan River, have demonstrated, many of these practices are far from sustainable.
“The globe’s oceans are a virtually inexhaustible source of water, but the process of removing its salt is expensive and energy intensive,” said Menachem Elimelech, a professor of chemical and environmental engineering at Yale and lead author of the study, which appears in the Aug. 5 issue of the journal Science…
The Future of Seawater Desalination, Original Article in Science Magazine In recent years, numerous large-scale seawater desalination plants have been built in water-stressed countries to augment available water resources, and construction of new desalination plants is expected to increase in the near future. Despite major advancements in desalination technologies, seawater desalination is still more energy intensive compared to conventional technologies for the treatment of fresh water.
Indian authorities on Monday worked to clean up an oil spill from a cargo ship that sank off Mumbai last week, with oil found on beaches and in water near the city’s shoreline.
It is reported that the oil was still eight to nine nautical miles from shore and the rate of the spill from the MV Rak Carrier had decreased from 1.5 to 2.0 tonnes per hour to about one tonne per hour over the last 24 hours…
Tohoku Tsunami Creates Antarctic Icebergs- NASA Video Nearly 50 square miles of ice broke off the Sulzberger Ice Shelf on the coast of Antarctica, resulting from waves generated by the Tohoku earthquake and tsunami that struck Japan in March 2011. Credit: NASA/Goddard.
By Patrick Lynch, NASA’s Goddard Space Flight Center, and Steve Koppes, University of Chicago
A NASA scientist and her colleagues were able to observe for the first time the power of an earthquake and tsunami to break off large icebergs a hemisphere away.
Kelly Brunt, a cryosphere specialist at Goddard Space Flight Center, Greenbelt, Md., and colleagues were able to link the calving of icebergs from the Sulzberger Ice Shelf in Antarctica following the Tohoku Tsunami, which originated with an earthquake off the coast of Japan in March 2011. The finding, detailed in a paper published online today in the Journal of Glaciology, marks the first direct observation of such a connection between tsunamis and icebergs.
The birth of an iceberg can come about in any number of ways. Often, scientists will see the towering, frozen monoliths break into the polar seas and work backwards to figure out the cause.
So when the Tohoku Tsunami was triggered in the Pacific Ocean on March 11 this spring, Brunt and colleagues immediately looked south. All the way south. Using multiple satellite images, Brunt, Emile Okal at Northwestern University and Douglas MacAyeal at University of Chicago were able to observe new icebergs floating off to sea shortly after the sea swell of the tsunami reached Antarctica.
To put the dynamics of this event in perspective: An earthquake off the coast of Japan caused massive waves to explode out from its epicenter. Swells of water swarmed toward an ice shelf in Antarctica, 8,000 miles (13,600 km) away, and about 18 hours after the earthquake occurred, those waves broke off several chunks of ice that together equaled about two times the surface area of Manhattan. According to historical records, this particular piece of ice hadn’t budged in at least 46 years before the tsunami came along.
And as all that was happening, scientists were able to watch the Antarctic ice shelves in as close to real-time as satellite imagery allows, and catch a glimpse of a new iceberg floating off into the Ross Sea.
“In the past we’ve had calving events where we’ve looked for the source. It’s a reverse scenario – we see a calving and we go looking for a source,” Brunt said. “We knew right away this was one of the biggest events in recent history – we knew there would be enough swell. And this time we had a source.”
Scientists first speculated in the 1970s that repeated flexing of an ice shelf – a floating extension of a glacier or ice sheet that sits on land – by waves could cause icebergs to break off. Scientific papers in more recent years have used models and tide gauge measurements in an attempt to quantify the impact of sea swell on ice shelf fronts.
The swell was likely only about a foot high (30 cm) when it reached the Sulzberger shelf. But the consistency of the waves created enough stress to cause the calving. This particular stretch of floating ice shelf is about 260 feet (80 meters) thick, from its exposed surface to its submerged base.
Before (left) and after (right) photos of the Sulzberger Ice Shelf illustrate the calving event associated with the Japan earthquake and resulting tsunami that occurred on March 11, 2011. The icebergs have just begun to separate in the left image. Credit: European Space Agency/Envisat
When the earthquake happened, Okal immediately honed in on the vulnerable faces of the Antarctic continent. Using knowledge of iceberg calving and what a NOAA model showed of the tsunami’s projected path across the unobstructed Pacific and Southern oceans, Okal, Brunt and MacAyeal began looking at what is called the Sulzberger Ice Shelf. The Sulzberger shelf faces Sulzberger Bay and New Zealand.
Through a fortuitous break in heavy cloud cover, Brunt spotted what appeared to be a new iceberg in MODerate Imaging Spectroradiometer (MODIS) data.
“I didn’t have strong expectations either way whether we’d be able to see something,” Brunt said. “The fastest imagery I could get to was from MODIS Rapid Response, but it was pretty cloudy. So I was more pessimistic that it would be too cloudy and we couldn’t see anything. Then, there was literally one image where the clouds cleared, and you could see a calving event.”
A closer look with synthetic aperture radar data from the European Space Agency satellite, Envisat, which can penetrate clouds, found images of two moderate-sized icebergs – with more, smaller bergs in their wake. The largest iceberg was about four by six miles in surface area – itself about equal to the surface area of one Manhattan. All the ice surface together about equaled two Manhattans. After looking at historical satellite imagery, the group determined the small outcropping of ice had been there since at least 1965, when it was captured by USGS aerial photography.
The proof that seismic activity can cause Antarctic iceberg calving might shed some light on our knowledge of past events, Okal said.
“In September 1868, Chilean naval officers reported an unseasonal presence of large icebergs in the southernmost Pacific Ocean, and it was later speculated that they may have calved during the great Arica earthquake and tsunami a month earlier,” Okal said. “We know now that this is a most probable scenario.”
MacAyeal said the event is more proof of the interconnectedness of Earth systems.
“This is an example not only of the way in which events are connected across great ranges of oceanic distance, but also how events in one kind of Earth system, i.e., the plate tectonic system, can connect with another kind of seemingly unrelated event: the calving of icebergs from Antarctica’s ice sheet,” MacAyeal said.
In what could be one of the more lasting observations from this whole event, the bay in front of the Sulzberger shelf was largely lacking sea ice at the time of the tsunami. Sea ice is thought to help dampen swells that might cause this kind of calving. At the time of the Sumatra tsunami in 2004, the potentially vulnerable Antarctic fronts were buffered by a lot of sea ice, Brunt said, and scientists observed no calving events that they could tie to that tsunami.
“There are theories that sea ice can protect from calving. There was no sea ice in this case,” Brunt said. “It’s a big chunk of ice that calved because of an earthquake 13,000 kilometers away. I think it’s pretty cool.”
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…
Since 36 dead wild boars have been found on the coast of north-western France this month, amid suspicion of algae poisoning, necropsies have been being carried out.
The first tests on six wild boars washed up on brittany’s beaches, showed that all but one, had hydrogen sulphide gas (emitted by rotting algae) in their lungs, confirming the suspicion toward the prior hypothesis that the wild boars suffocated from the poisonous gases emitted by rotting green algae.
However, Hydrogen sulphide gas (H2S) has not been found in the sixth animal, preventing the testers from concluding they’d been killed from breathing fumes from rotting seaweed.
Test results on the remaining boars haven’t been released yet.
Some beaches in Brittany are regularly hit by the algae, but the problem has worsened in recent years.
Environmentalists and officials say it is a result of the nitrates in fertilisers used by the region’s farmers.
According to a Guardian report, “local environmentalists have long campaigned against the dangers of what has become known as Brittany’s “killer” green algae. It has been affecting the rugged north Breton coastline for decades but has increased in recent years, causing the death of a worker who was clearing it in 2009, as well as killing dogs and a horse walking on the beach. Guardian
The French Government has launched a massive long-term plan to clear the beaches of algae, hauling away the noxious growth with bulldozers. But campaigners say nothing will change unless Brittany’s powerful agriculture and food industry cuts its nitrates use.
The algae is harmless until it dries and then decomposes, giving off a foul smell. Pockets of the toxic gas can become trapped under its crust. Thousands of tonnes of green algae have been cleared from the Brittany coast this year. In Finistère the amount of algae has grown since last year.
In a front-page editorial entitled, Green Algae: The Unbearable Denial, Le Monde said the French state, in thrall to lobby groups, was downplaying the role of agricultural pollution in the proliferation of noxious and toxic algae along the coasts.
Algues vertes : l’insupportable déni, Le Monde Lorsque les faits sont importuns, il suffit de mettre en doute leur existence. Ce détestable principe semble avoir un avenir radieux, dès lors que remédier à des dégâts environnementaux ou sanitaires indispose des intérêts économiques.
The US Interior Department has opened the doors to Shell’s proposal for four shallow water exploration wells in Alaska’s Beaufort Sea to start in July 2012, said the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE).
Final approval requires Shell to obtain permits from other US agencies including the Environmental Protection Agency, the US Fish and Wildlife Service, and National Marine Fisheries Service…
In Qingdoo, Shandong Province of China, the coastal waters are covered with algae called enteromorpha prolifera (ulva prolifera). Though the green algae is not poisonous per se, it can consume large amounts of oxygen that can threaten marine life.
The North China Sea Marine Forecasting Center of State Oceanic Administration cited a July 23 monitoring statistics as saying that about 19,050 square km of seawater in the Yellow Sea were found with algae, while some 500 square km were covered with the plant…
Acute toxicity of live and decomposing green alga Ulva ( Enteromorpha) prolifera to abalone Haliotis, Harvard / The Smithsonian/NASA data From 2007 to 2009, large-scale blooms of green algae (the so-called “green tides”) occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. This study examined the toxic effects of Ulva (Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.
Are Blue-Green Algae Toxic? EPA Species of blue-green algae can include both toxin-producing (Harmfull Algae Bloom, HAB) and non-toxin-producing strains. Little is known about the environmental conditions that trigger toxin production, and there is no way to tell just by looking at a bloom whether or not it will produce toxins.
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.