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Each week we write about the science behind environmental protection. Previous Science Wednesdays.By Jonathan Herrmann, P.E., BCEEI have spent almost my entire career in EPA’s Office of Research and Development. During that time, I’ve been involved in many areas of research related to…
Tsunamis are ocean waves caused by large earthquakes and landslides that occur near or under the ocean. Scientists do not use the term 'tidal wave' because these waves are not caused by tides. Tsunami waves are unlike typical ocean waves generated by wind and storms. When tsunamis approach…
Visit the USGS National Wildlife Health Center (NWHC) web pages at http://www.nwhc.usgs.gov/ . The National Wildlife Health Center was established in 1975 as a biomedical laboratory dedicated to assessing the impact of disease on wildlife and to identifying the role of various pathogens in…
Although it may seem that we are having more earthquakes, earthquakes of magnitude 7.0 or greater have remained fairly constant throughout this century and, according to our records, have actually seemed to decrease in recent years. There are several reasons for the perception that the number of…
Historical USGS topographic maps are important map resources that are not readily available. Therefore, the USGS has begun a project to convert all these historical printed topographic quadrangles to digital formats (initially GeoPDF). Learn more at http://nationalmap.gov/historical/ . …
Earthquakes occur on faults - strike-slip earthquakes occur on strike-slip faults , normal earthquakes occur on normal faults , and thrust earthquakes occur on thrust or reverse faults. When an earthquake occurs on one of these faults, the rock on one side of the fault slips with respect to the…
During the three giant caldera-forming eruptions that occurred between 2.1 million and 640,000 years ago, tiny particles of volcanic debris ( volcanic ash ) covered much of the western half of North America, likely a third of a meter deep several hundred kilometers from Yellowstone and several…
Lava and Lava Flows The temperature of basalt lava at Kilauea reaches 1,160 degrees Celsius (2,120 degrees Fahrenheit). -- USGS/VHP Website, 1998 The tube system (lava tubes) of episode 53 (Pu'u O'o eruption, Hawaii) carried lava for 10 kilometers (6 miles) from the vent to the sea. So…
See Multidisciplinary Center for Earthquake Engineering Research
Moment is a physical quantity proportional to the slip on the fault times the area of the fault surface that slips; it is related to the total energy released in the EQ. The moment can be estimated from seismograms (and also from geodetic measurements). The moment is then converted into a number…
Most volcanoes provide various types of warnings before eruptions begin. Although an explosive eruption could occur without warning, some premonitory events more likely will precede the next eruption. Steam-blast eruptions could occur with little or no warning as superheated water flashes to steam;…
There are many different reasons for why animals become endangered, especially habitat loss. An animal's habitat is where they live, eat, and raise their young. Protecting endangered and threatened species and restoring them to a secure status in the wild is the primary objective of the…