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Each week we write about the science behind environmental protection. Previous Science Wednesdays.By Dimetrius SimonRecently I attended “Emerging Science for Environment Health Decisions” conference as a student contractor to the EPA. I had just started and this was a new opportunity for me to…
Yes and they're free. Nearly all map layers presented within our Map Maker are available for use outside the National Atlas. You can download these map layers at no cost using file transfer protocol (FTP). See our Raw Data Download page for more information about downloading National Atlas map…
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/ . …
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…
An earthquake is caused by a sudden slip on a fault . The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust…
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…
Intensity scales, like the Modified Mercalli Scale and the Rossi-Forel scale, measure the amount of shaking at a particular location. So the intensity of an earthquake will vary depending on where you are. Sometimes earthquakes are referred to by the maximum intensity they produce. Magnitude…
The short answer is - a rolling motion means you are probably far away from the earthquake; a sharp jolting motion means you are probably close to the earthquake. Three factors primarily determine what you feel in an earthquake: Magnitude (you feel more intense shaking from a big earthquake than…
The USGS Publications Warehouse ( http://pubs.usgs.gov/ ) has released a new interface and a variety of new content and features. The new version of this tool now includes citations for USGS-authored content including journal articles, books, book chapters, proceedings, and other research…
Continuous real-time water quality information is at http://water.usgs.gov/waterwatch/wqwatch/ . These data are limited to measurable characteristics such as temperature, turbidity, specific conductance (salinity), dissolved oxygen, and pH (acidity). WaterQualityWatch is a USGS web site that…
Not only will the credit legend, in the lower left-hand corner of the map, list the date and source of the data, but metadata will contain this information as well. The quadrangle-specific metadata are embedded in the GeoPDF. Metadata can be opened by clicking on the paper clip icon in the lower…