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An Overhead View of the Underground GrindThe purpose of this map is to show the location of and evidence for recent movement on active fault traces within the Hayward Fault Zone, California. The mapped traces represent the integration of the following three different types of data: (1) geomorphic expression, (2) creep (aseismic fault slip),and (3) trench exposures.This publication is a major revision of an earlier map (Lienkaemper, 1992), which both brings up to date the evidence for faulting and makes it available formatted both as a digital database for use within a geographic information system (GIS) and for broader public access interactively using widely available viewing software. The pamphlet describes in detail the types of scientific observations used to make the map, gives references pertaining to the fault and the evidence of faulting, and provides guidance for use of and limitations of the map......... Posted by: Tyler Permalink Source Ocean 'dead zones' posing extinction threat
Dead zones are occurring in many areas along the coasts of major continents, and they are spreading over larger areas of the sea floor. Because very few organisms can tolerate the lack of oxygen in these areas, they can destroy the habitat in which numerous organisms make their home.
The finding, by Rudolf Wu, Ph.D., and his colleagues at the City University of Hong Kong, raises new concerns about vast areas of the world's oceans, known as "dead zones," that lack sufficient oxygen to sustain most sea life. Fish and other creatures trapped in these zones often die. Those that escape may be more vulnerable to predators and other stresses. This new study, Wu says, suggests these zones potentially pose a third threat to these species - an inability of their offspring to find mates and reproduce. The scientists found that low levels of dissolved oxygen, also known as hypoxia, can induce sex changes in embryonic fish, leading to an overabundance of males. As these predominately male fish mature, it is unlikely they will be able to reproduce in sufficient numbers to maintain sustainable populations, Wu says. Low oxygen levels also might reduce the quantity and quality of the eggs produced by female fish, diminishing their fertility, he adds......... Posted by: Tyler Permalink Source Eruption of Yellowstone's Southern TwinNorth America isn't the only continent that's experienced super-colossal volcanic eruptions in the recent geologic past. The massive explosion of the almost unknown Vilama Caldera in Argentina appears to have matched Yellowstone's last continent-blanketing blast. It may, in fact, be just one of several unappreciated supervolcanoes hidden in a veritable mega-volcano nursery called the Eduardo Avaroa Caldera Complex, located in the inhospitable Puna-Altiplano region near the tri-section of Argentina, Bolivia, and Chile."Vilama Caldera formed during a single event that emitted approximately 2000 cubic kilometers (almost 500 cubic miles) of pyroclastic material," said geologist Miguel M. Soler of the National University of Jujuy in San Salvador de Jujuy, Argentina. The volume of ash and pyroclastic material, called ignimbrites, produced by the 8.4 million-year-old eruption, and the size of the associated caldera, put it among the world's largest known eruptions, he says. "In contrast, for example, Yellowstone produced its important volumes of ignimbrites and lavas in three cataclysmic events. Eruptions at 2.0, 1.3, and 0.6 million years ago ejected huge volumes of rhyolite magma, and each formed a caldera and extensive layers of thick pyroclastic flow deposits," said Soler. Soler will present some of the recent groundbreaking work on Vilama supervolcano on Monday, 3 April at Backbone of the Americas - Patagonia to Alaska. The meeting is co-convened by the Geological Society of America and the Asociacion Geologica Argentina, with collaboration of the Sociedad Geologica de Chile. The meeting takes place 3-7 April in Mendoza, Argentina......... Posted by: Tyler Permalink Source Twenty Two Years And Still Ticking
The nearly 11,000 acres affected by the Sierra fire in Orange County, California are seen in these Landsat 5 images. The image on the left was acquired three days prior to the breakout of the fire. The image on the right was acquired the day the fire was contained. The burned areas show as the deep red tones in the center of the right image. View in higher resolution
Because of the sophisticated equipment on board, engineers anticipated a life of a mere two years, with a goal of three years of collecting data over the landmass of the planet. Instead, Landsat 5 has become the longest continuously serving observation system in the U.S. civilian fleet. The track record for this satellite is nothing short of phenomenal. Landsat satellites have been collecting images of the Earth's surface for more than thirty years. NASA launched the first Landsat satellite in 1972, and the most recent one, Landsat 7, in 1999. Instruments onboard the satellites have acquired millions of images of the Earth. These images provide a unique resource for people who work in agriculture, geology, forestry, regional planning, education, mapping, and global change research......... Posted by: Tyler Permalink Source Rivers Indicate Earlier Snowmelt
"We studied rural, unregulated rivers with more than 50 years of USGS and Environment Canada river flow data," explained Glenn Hodgkins, lead author and hydrologist at the USGS Maine Water Science Center. "Some 179 rivers in eastern North America met the criteria of our study with 147 in the United States from the Dakotas to New England and 32 in Canada from Manitoba to Newfoundland. These rivers are sensitive to changes in precipitation and temperature," added Robert Dudley, co-author of study. The researchers compared the dates by which half of the total volume of winter-spring runoff has flowed past a river gaging station in each year. Most rivers north of 44 degree north latitude--roughly from southern Minnesota and Michigan through northern New York and southern Maine--showed earlier winter-spring streamflows. In contrast, a number of stations south of this line in Iowa, southern Wisconsin, and northern Illinois had later streamflows. Changes in average monthly flows support these results--there are high percentages of rivers north of 44 degree north latitude with increases in January, February, and March streamflows and relatively high percentages of rivers with decreases in May and June......... Posted by: Tyler Permalink Source New Test Of General Relativity?
Just as a moving electrical charge creates a magnetic field, so a moving mass generates a gravitomagnetic field. As per Einstein's Theory of General Relativity, the effect is virtually negligible. However, Martin Tajmar, ARC Seibersdorf Research GmbH, Austria; Clovis de Matos, ESA-HQ, Paris; and his colleagues have measured the effect in a laboratory. Their experiment involves a ring of superconducting material rotating up to 6 500 times a minute. Superconductors are special materials that lose all electrical resistance at a certain temperature. Spinning superconductors produce a weak magnetic field, the so-called London moment. The new experiment tests a conjecture by Tajmar and de Matos that explains the difference between high-precision mass measurements of Cooper-pairs (the current carriers in superconductors) and their prediction via quantum theory. They have discovered that this anomaly could be explained by the appearance of a gravitomagnetic field in the spinning superconductor (This effect has been named the Gravitomagnetic London Moment by analogy with its magnetic counterpart)......... Posted by: Tyler Permalink Source Warmer Ocean Waters Reducing Ice Worldwide
Photo of Dr. Bob Bindschadler on an expedition. Credit: NASA
This conclusion appears in an article by Robert Bindschadler, a glaciologist at NASA's Goddard Space Flight Center in Greenbelt, Md. His article is in the March 24 issue of Science magazine. Temperatures collected from ships and buoys showed a warming of all oceans. That increase began before satellite sensors detected temperature increases of sea surfaces. Most of the warming was limited to the oceans' upper 1000 meters (.62 mile), except in the North Atlantic. In the cold North Atlantic waters, heat penetrated even deeper. This warming has increased the melting of sea ice in the North Atlantic. Overall ocean heat content changes are monitored by ocean altimetry missions like TOPEX and Jason-1 and the on site Argo buoy network floats that broadcast measurements to a satellite. These provide information on ocean temperatures. It has another effect, however, which may potentially be of great significance to sea level rise, and that is that these warm waters are beginning to melt the underside of the floating fringes of the Greenland ice sheet, even at great depths, It is these fringes that have been holding back vast stores of ice locked up in the Greenland ice sheet, and as this ice has been melting, the glaciers have hastened their flow to the sea......... Posted by: Tyler Permalink Source Space Tool For Clean Drinking Water
Meeting this goal will demand reliable, current data and information about how much water is stored in large lakes, rivers and reservoirs around the world - which radar altimetry can provide. In the past, hydrological information could often be difficult to obtain by ground-based gauge instruments due to the inaccessibility of the region, the sparse distribution of gauge stations or the slow dissemination of data due to national policy. Radar altimetry can avoid these obstacles because it is located on satellites 800 to 1300 kilometres above the Earth and is able to measure large lakes' surface water height to two centimetres accuracy and rivers to ten centimetres by sending 1800 separate radar pulses over bodies of water per second and recording how long their echoes take to bounce back. In addition, these data are available in near-real time. Today there are several teams in the world involved in radar altimetry over inland water, using satellite data from ESA, NASA and the French Space Agency (CNES). Hydrologists from each of these research teams met at the '15 Years of Progress in Radar Altimetry' symposium, organised by ESA and the French Space Agency (CNES) in Venice Lido, Italy, from 13-18 March 2006, to discuss the abilities of past and current altimeters for monitoring the Earth's changing inland water resources......... Posted by: Tyler Permalink Source Polar neutrino observatory
Robert Paulos, associat director for the IceCube project, holds one of the digital optical modules that power the IceCube neutrino telescope. Image courtesy of the IceCube project.
Researchers leading a consortium building the massive neutrino telescope known as IceCube say that this year they have nearly doubled the size of the detector now under construction at the National Science Foundation's Amundsen-Scott South Pole Station. NSF, through a joint program of its Office of Polar Programs and its Mathematical and Physical Sciences Directorate, is contributing more than $240 million to the international partnership that is building the detector, which will cost $272 million overall. Eventhough work can only take place from October through February-the fleeting and still frigid summer season at the Pole-the extent and pace of construction this year means that the observatory may soon begin scientific operations. IceCube is scheduled for completion in 2011. "The news is good all around," says Francis Halzen, the University of Wisconsin-Madison physics professor leading the effort. Halzen and others leading the effort report that IceCube- which depends on strings of light-sensing modules frozen deep in crystal clear Antarctic ice-has grown this austral summer by 480 basketball-sized optical modules. Deployed on long cables in 1.5-mile deep holes bored by a unique hot-water drill, the modules will be used to detect the fleeting but telltale signatures of high-energy cosmic neutrinos as they flit through the Earth......... Posted by: Brooke Permalink Source Deep-Ocean Whirlpool detection using Satellites
Using sensor data from several U.S. and European satellites, scientists from the University of Delaware, NASA's Jet Propulsion Laboratory, and the Ocean University of China have developed a method to detect super-salty, submerged eddies called "Meddies" that occur in the Atlantic Ocean off Spain and Portugal at depths of more than a half mile. These warm, deep-water whirlpools, part of the ocean's complex circulatory system, help drive the ocean currents that moderate Earth's climate. The research marks the first time researchers have been able to detect phenomena so deep in the ocean from space -- and using a new multi-sensor technique that can track changes in ocean salinity. The lead author of the study was Xiao-Hai Yan, Mary A. S. Lighthipe Professor of Marine Studies at the University of Delaware and co-director of the UD Center for Remote Sensing. His collaborators included Young-Heon Jo, a postdoctoral researcher in the UD College of Marine Studies, W. Timothy Liu from NASA's Jet Propulsion Laboratory in Pasadena, California, and Ming-Xia He, from the Ocean Remote Sensing Institute at the Ocean University of China in Qingdao, China. Their results are published in the recent issue of the American Meteorological Society's Journal of Physical Oceanography......... Posted by: Tyler Permalink Source |
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