Algae-based fuel is one of many options among the array of possible future energy sources. New University of Virginia research shows that while algae-based transportation fuels produce high energy output with minimal land use, their production could come with significant environmental burdens.
From an environmental impact standpoint, algae-based fuel has mixed performance, compared to other biomass sources. Algae-based biodiesel production uses more energy, in the form of petroleum-powered processes, than other biofuels. Additionally, algae-based biodiesel and bioelectricity production processes also require substantial amounts of water and emit more greenhouse gases.
The leatherback turtle has a unique biology among turtles. Its circulatory system and internal shell structure enable it to withstand cooler temperatures and dive deeper than other species. It often turns up in UK waters.
The Marine Conservation Society (MCS) wants the public to report any turtles they see during August, the peak time to spot the creatures in UK waters, to see if there are any hotspots for them or areas where conservation measures are needed…
NOAA-supported scientists found the size of this year’s Gulf of Mexico dead zone to be 6,765 square miles.
Researchers had predicted the potential for a record sized dead zone between 8,500 and 9,421 square miles due to the spring flooding of the Mississippi River and the associated large loads of nutrients running off into the Gulf, but strong winds and waves associated with Tropical Storm Don disrupted the western portion of the dead zone.
The research cruise, led by Nancy Rabalais, Ph.D., executive director of the Louisiana Universities Marine Consortium, found this year’s dead zone to be nearly equal to the land area of the state of New Jersey.
The average size of the dead, or hypoxic, zone over the past five years has been 6,688 square miles, very close to this year’s measurement and much larger than the 1,900 square mile goal set by the Gulf of Mexico/Mississippi River Watershed Nutrient Task Force. Last year’s dead zone measured approximately 7,722 square miles.
In addition to surveys in the traditional region of the dead zone, Rabalais’ research team documented a large area of hypoxia east of the Mississippi River in mid-July.
“Although Tropical Storm Don disrupted part of the hypoxic zone, our monitoring over the past several months indicated the spring floods expanded the dead zone region,” said Rabalais. “However, sampling the hypoxic bottom layer on a ship rolling in 6-10 foot waves presented safety and sampling issues that interfered with precise measurements at some stations. For these reasons, the size of the measured hypoxic zone was smaller than just before the storm, and is probably under-estimated.”
The dead zone is fueled by nutrient runoff from agricultural and other human activities in the Mississippi River watershed, which stimulates an overgrowth of algae that sinks, decomposes and consumes most of the life-giving oxygen supply in bottom waters. The hypoxic zone off the coast of Louisiana and Texas forms each summer and threatens valuable commercial and recreational Gulf fisheries.
These fisheries are critical to the economy. For example, in 2009, the dockside value of commercial fisheries in the Gulf was $629 million. Nearly three million recreational fishers, taking 22 million fishing trips, further contributed more than $1 billion to the Gulf economy.
“Despite fluctuations in size due to each year’s weather conditions, these chronic, recurring hypoxic zones every summer represent a significant threat to Gulf ecosystems,” said Robert Magnien, Ph.D., director of NOAA’s Center for Sponsored Coastal Ocean Research. “Until we achieve a substantial reduction in nutrient pollution from the Mississippi River watershed, we will continue to experience extended periods of time each year when critically-needed habitat is unavailable for many marine organisms.”
Excerpts; By Oregon State University, in Science Daily
A team of scientists just discovered a new eruption of Axial Seamount, an undersea volcano located about 250 miles off the Oregon coast, and one of the most active and intensely studied seamounts in the world.
What makes the event so intriguing is that the scientists had forecast the eruption starting five years ago, the first successful forecast of an undersea volcano…
The giant earthquake that struck Japan this year not only shook the Earth, but also rattled the highest layer of the atmosphere, scientists find. This research could lead to a new type of early warning system for devastating tsunamis and earthquakes.
The magnitude 9 quake that struck off the coast of Tohoku in Japan in March unleashed a catastrophic tsunami, ushered in what might be the world’s first complex megadisaster and set off microquakes and tremors around the globe.
Past research revealed the surface motions and tsunamis that earthquakes generate can also trigger acoustic waves in the atmosphere. These waves can reach all the way to the ionosphere, one of the highest layers of the atmosphere.
Now scientists report the Tohoku quake generated the largest such disturbances seen yet, creating ripples in electrically charged particles reaching nearly 220 miles (350 kilometers) above the Earth.
The wave fronts were accompanied by circular ripples travelling “close to a tsunami speed of about 720-800km per hour”, say researchers led by physicist Jann-Yenq Liu at the Institute of Space Science at Taiwan’s National Central University…
In response to Ghana’s gravely eroding coastline, the Government decided on a costly and controversial project: the building of a 68 million euro, 30 kilometres “Ada Sea Defense Wall”, to “salvage the people in the area from the ravages of the sea”, as Vice-President, Mr John Dramani Mahama, announced last Saturday.
The real story of coastal erosion is not about what lies at the water’s edge, but what occurs beneath the waves offshore.
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.”