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Each week we write about the science behind environmental protection. Previous Science Wednesdays.By Paul T. Anastas, Ph.D.A dedicated team of scientists in EPA’s Integrated Risk Information System (IRIS) program works to assess the hazards that chemicals pose to human health. The assessments they…
Nitrate (NO 3 ) is a common inorganic form of nitrogen. Chemically, it is an anion with a single negative charge, consisting of one atom of nitrogen and three atoms of oxygen. Because it is an anion, it is soluble in water. Plants normally use nitrate as their source of the nitrogen needed by all…
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…
An up-to-date Web browser installed with the Shockwave plug-in is all the software you need to use nationalatlas.gov™. Please make certain that your browser allows pop-up windows to open. We also suggest that you turn off the display of scripting errors in your browser’s Internet options or…
Floods are a dangerous hazard throughout the world, and most people underestimate the power of flood waters. On average, in the United States, about 165 people are killed and about $2 billion of damage occurs each year. Several types of data can be collected to assist hydrologists predict when and…
We generally emphasize the following four points: a) Select a coordinate system (also called a "position format") you feel comforatble using. We suggest using Universal Transverse Mercator (UTM) or latitude/longitude. Most users find UTM coordinates easier to locate on USGS…
No. Probabilities are estimated from the rate of aftershocks and these are sometimes confused with the prediction of a particular event.
Yes. The list is at: "Major Catastrophic Landslides of the 20th Century"
You can purchase topographic maps several ways: Download or online from the USGS Store at http://store.usgs.gov Click on Maps in the left margin or click on the Map Locator near the center of the screen. Topographic maps in GeoPDF format are available for free download by using the Map…
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…
Have you visited the Children's Butterfly Site ? Although it is geared toward young people, the site contains a wealth of information on butterflies, including photo galleries (Common Butterflies of Western Europe and Great Britain, and Common Butterflies of North America), as well as links to…
Yes. The main body of subsurface water is found in the saturated zone of aquifers. Aquifers can be only a few feet below the surface or more than a thousand feet deep. Aquifers are the primary source of drinking water in arid and semi-arid parts of the United States where the amount of surface water…