Tag: Pacific

Filter By:

Filter

Rising carbon dioxide levels not tied to Pacific Ocean

Deep ocean was not an important source of carbon during glacial times After the last ice age peaked about 18,000 years ago, levels of atmospheric carbon dioxide rose about 30 percent. Scientists believe that the additional carbon dioxide -- a heat-trapping greenhouse gas -- played a key role in warming the planet and melting the continental ice sheets. They have long hypothesized that the source of the gas was the deep ocean.But a new study by a University of Michigan paleoclimatologist and two colleagues suggests that the deep ocean was not an important source of carbon during glacial times. The finding will force researchers to reassess their ideas about the fundamental mechanisms that regulate atmospheric carbon dioxide over long time scales."We're going back to the drawing board. It's certainly fair to say that we need to have some other working hypotheses at this point," said U-M paleoclimatologist David Lund, lead author of a paper in the journal Nature Geoscience."If we can improve our understanding of the carbon cycle in the past, we will be better positioned moving forward as CO2 levels rise due to anthropogenic causes," said Lund, an assistant professor in the U-M Department of Earth and Environmental Sciences. ...

Read more

Hurricane Hilary Forms In The Pacific

Strengthened into a small, but powerful Category 4 storm in the pacific Forecasters say Hurricane Hilary has strengthened into a small, but powerful Category 4 storm in the Pacific.Hilary's maximum sustained winds were near 135 mph (217 kph) Thursday. The hurricane is not forecast to make landfall, though officials say it is expected to rake Mexico's coast with wind, rain and heavy surf.The U.S. National Hurricane Center says a tropical storm warning is in effect for Mexico's coast from Lagunas de Chacahua to Punta San Telmo. A tropical storm watch is in effect for west of Punta San Telmo to Manzanillo.Hilary is centered about 85 miles (137 kilometers) southwest of Acapulco, Mexico, and is moving west-northwest.In the Atlantic, Tropical Storm Ophelia is weakeningSource: Huffington Post

Read more

Nitrate pollution in Pacific Ocean

Rising nitrate levels in the northwest Pacific Ocean can influence marine ecology Rising nitrate levels in the northwest Pacific Ocean could alter the makeup of marine plants and influence marine ecology, U.S. and Korean researchers say.Atmospheric and riverine pollution off the coasts of Korea and Japan that is changing the ratio of nitrate to phosphorus has researchers saying they're concerned about ecological effects."Normally in a marine environment nitrate is the limiting factor, but increased nitrate in the ocean can spur growth and create a situation where phosphorus becomes the nutrient in short supply," Raymond G. Najjar, Penn State professor of oceanography, said."This change in nutrients could favor organisms that are better suited for high nitrate and low phosphorus."The effects of man-made nitrate pollution have been shown to be significant in local lakes, streams and estuaries in Norway, Sweden and the United States, researchers said, but this is the first study of such effects in open ocean waters."This is the first evidence of increases in nitrate in ocean waters, not in an enclosed estuary like the Chesapeake Bay," Najjar said. "These are large, very deep bodies of water and it is surprising to see increased nitrate in these large seas."A significant ...

Read more

Radioactive cesium from Fukushima on tour of Pacific Ocean

It will wash up on Japan's shores again in between 20 and 30 years Scientists from the government's Meteorological Research Institute and the Central Research Institute of the Electric Power Industry announced their findings at a meeting of the Geochemical Society of Japan this week, adding that some of the cesium will also flow into the Indian Ocean and, eventually, reach the Atlantic.The scientists estimated that some 3,500 terabecquerels of cesium-137 was released into the sea directly from the plant between March 11, when the earthquake and tsunami struck, and the end of May. Another 10,000 terabecquerels of cesium fell into the ocean after escaping from the reactors in the form of steam.One terabecquerel is a trillion becquerels, the standard measure of radiation, and the Japanese government has set the permissible level of iodine-131 for vegetables and fish at 2,000 becquerels per kilogram (2.2lbs).Cesium is considered a more serious threat, however, because of its relatively long half-life. Cesium has a half-life of around 30 years, can accumulate in muscles and is a known cause of cancer.The researchers believe that the cesium has initially dispersed into the Pacific from the coast of Fukushima Prefecture but will be taken to the southwest ...

Read more

Economists say sea level rise would be costly

A recent study hows a surge in the Pacific Ocean because of climate change Economists predict erosion from rising sea levels could cost California hundreds of millions of dollars in lost tourism and tax revenues as beaches shrink and buildings would have to be protected, according to a new report.A study by San Francisco State University released Tuesday shows a surge in the Pacific Ocean because of climate change, and accompanying storms and erosion, would batter California's shoreline, diminishing the appeal of coastal areas and threatening structures with flood damage.The eroding beaches will also destroy scores of animal habitats, the report finds."More than 80 percent of Californians live in coastal communities, and California's beaches support local economies and critical natural species," said Philip King, the study's author and an economics professor at San Francisco State.The study commissioned by the California Department of Boating and Waterways examined sea level projections at five beach communities.As the authors note, coastal storms and beach erosion are a common event that have already shaped the geography of coastal environments. Yet, because sea levels are projected to rise and storms are expected to be more intense due to a warming planet, the effects over the next ...

Read more

Scientists study earthquake triggers in Pacific Ocean

They may help explain the cause of large earthquakes similar to the Japan earthquake New samples of rock and sediment from the depths of the eastern Pacific Ocean may help explain the cause of large, destructive earthquakes similar to the Tohoku Earthquake that struck Japan in mid-March.Nearly 1500 meters (almost one mile) of core collected from the ocean floor near the coast of Costa Rica reveal detailed records of approximately 2 million years of tectonic activity along a seismic plate boundary.The samples were retrieved with the scientific drilling vessel JOIDES Resolution during the recent month-long Integrated Ocean Drilling Program (IODP) Costa Rica Seismogenesis Project (CRISP) Expedition. Participating scientists aim to use the samples better understand the processes that control the triggering of large earthquakes at subduction zones, where one plate slides beneath another."We know that there are different factors that contribute to seismic activity - these include rock type and composition, temperature differences, and how water moves within the Earth's crust," explained co-chief scientist Paola Vannucchi (University of Florence, Italy), who led the expedition with co-chief scientist Kohtaro Ujiie (University of Tsukuba, Japan). She added, "but what we don't fully understand is how these factors interact with one another and ...

Read more
Page 10 of 10 1 9 10