Tag Archives: sea level

Study Offers Economical Solutions for Maintaining Critical Delta Environments

Millions of people across the world live or depend on deltas for their livelihoods.

Formed at the lowest part of a river where its water flow slows and spreads into the sea, deltas are sediment-rich, biodiverse areas, a valuable source of seafood, fertile ground for agriculture, and host to ports important for transportation.

At least half of the deltas around the world are so-called “wave dominated deltas” – open to the sea and under the impact of wave erosion. And many more deltas will come under wave dominance as dammed rivers carry less and less sediment. In a warming climate, sea levels are rising and storms are increasing in frequency and severity, posing threats to these deltas and the people and habitats dependent on them. (more…)

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Scientists Image Vast Subglacial Water System Underpinning West Antarctica’s Thwaites Glacier

AUSTIN, Texas — In a development that will help predict potential sea level rise from the Antarctic ice sheet, scientists from The University of Texas at Austin’s Institute for Geophysics have used an innovation in radar analysis to accurately image the vast subglacial water system under West Antarctica’s Thwaites Glacier. They have detected a swamp-like canal system beneath the ice that is several times as large as Florida’s Everglades.

The findings, as described last week in the Proceedings of the National Academy of Sciences, use new observational techniques to address long-standing questions about subglacial water under Thwaites, a Florida-sized outlet glacier in the Amundsen Sea Embayment considered a key factor in projections of global sea level rise. On its own, Thwaites contains enough fresh water to raise oceans by about a meter, and it is a critical gateway to the majority of West Antarctica’s potential sea level contribution of about 5 meters. (more…)

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‘A better path’ toward projecting, planning for rising seas on a warmer Earth

More useful projections of sea level are possible despite substantial uncertainty about the future behavior of massive ice sheets, according to Princeton University researchers.

In two recent papers in the journals Nature Climate Change and the Proceedings of the National Academy of Sciences (PNAS), the researchers present a probabilistic assessment of the Antarctic contribution to 21st-century sea-level change. Their methodology folds observed changes and models of different complexity into unified projections that can be updated with new information. This approach provides a consistent means to integrate the potential contribution of both continental ice sheets — Greenland and Antarctica — into sea-level rise projections. (more…)

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Long-Term Sea Level Rise Could Cost Washington, D.C. Billions

College Park, MD – A University of Maryland study projects that Washington, D.C. city and federal property could suffer billions of dollars in damage if sea level rise from global warming increases over the next century. Potential for significant damage will be even greater in the event of extreme weather like Hurricane Sandy

The study by Civil and Environmental Engineering Professor Bilal Ayyub, Haralamb Braileanu and Naeem Qureshi, of the Clark School of Engineering’s Center for Technology and Systems Management, looks at possible long term effects of projected sea level rise on Washington, D.C. real-estate property and government infrastructure. They conclude that over the next 100 years, continuing sea level rise could cause damages of more than $24.6 billion to Washington’s commercial property, museums, and government agencies. (more…)

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Why Are Coastal Salt Marshes Falling Apart?

Too many nutrients can cause extensive loss of marshes

Salt marshes have been disintegrating and dying over the past two decades along the U.S. Eastern Seaboard and other highly developed coastlines without anyone fully understanding why.

This week in the journal Nature, scientist Linda Deegan of the Marine Biological Laboratory (MBL) in Woods Hole, Mass., and colleagues report that nutrients–such as nitrogen and phosphorus from septic and sewer systems and lawn fertilizers–can cause salt marsh loss.

“Salt marshes are a critical interface between the land and sea,” Deegan says. “They provide habitat for fish, birds and shellfish, protect coastal cities from storms and take nutrients out of the water from upland areas, which protect coastal bays from over-pollution.” (more…)

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Scientists Discover New Site of Potential Instability in West Antarctic Ice Sheet

AUSTIN, Texas — Using ice-penetrating radar instruments flown on aircraft, a team of scientists from the U.S. and U.K. have uncovered a previously unknown sub-glacial basin nearly the size of New Jersey beneath the West Antarctic Ice Sheet (WAIS) near the Weddell Sea. The location, shape and texture of the mile-deep basin suggest that this region of the ice sheet is at a greater risk of collapse than previously thought.

Team members at The University of Texas at Austin compared data about the newly discovered basin to data they previously collected from other parts of the WAIS that also appear highly vulnerable, including Pine Island Glacier and Thwaites Glacier. Although the amount of ice stored in the new basin is less than the ice stored in previously studied areas, it might be closer to a tipping point. (more…)

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Global Sea Level Likely to Rise as Much as 70 Feet in Future Generations

*Scientists looked back in time–in the geologic record–to see the future*

Even if humankind manages to limit global warming to 2 degrees Celsius (3.6 degrees Fahrenheit)–as the Intergovernmental Panel on Climate Change recommends–future generations will likely have to deal with a completely different world.

One with sea levels 40 to 70 feet higher than at present, according to research results published this week in the journal Geology. (more…)

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Rising Seas Put Millions of Americans at Risk for Flooding

New estimates suggest more U.S. land prone to flooding than previously thought.

About 3.7 million Americans are at risk for flooding as the sea level continues to rise in the coming century, according to a new study from a team that includes University of Arizona researchers.

Areas on the south Atlantic Seaboard and surrounding the Gulf of Mexico appear to be most prone to future flooding. In terms of numbers of people at risk, Florida is the most vulnerable, closely followed by Louisiana, California, New York and New Jersey. (more…)

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