Remembering 9/11
Sunday marks the 10th anniversary of the terrorist attacks in New York City, Washington, DC, and Shanksville, PA. This is a time to reflect, to honor those who lost their lives, and to stand with their families and loved ones.Please observe a moment of silence on September 11 at 1 p.m. Eastern…
Are earthquake probabilities or forecasts the same as prediction?
No. Probabilities are estimated from the rate of aftershocks and these are sometimes confused with the prediction of a particular event.
How can I search for and order historical USGS topographic maps?
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/ . …
How can I find out about tsunamis?
For information on current or recent tsunamis, try: Pacific Tsunami Warning Center West Coast and Alaska Tsunami Warning Center Current Messages Recent Tsunamis Recent Events - from the University of Washington Database of tsunami information - from NOAA Other organizations in…
How much oil does the Bakken Formation produce and how does this compare to what the United States uses?
The USGS does not maintain statistics on oil production or information on consumption. However, production information can be obtained from publicly available sources like the North Dakota Department of Mineral Resources, Oil and Gas Division, https://www.dmr.nd.gov/oilgas/bakkenwells.asp and/or…
What is a fault and what are the different types?
A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake - or may occur slowly, in the form of creep . Faults may range in length from a few millimeters to thousands of…
What is the difference between a tsunami and a tidal wave?
Although both are sea waves, a tsunami and a tidal wave are two different unrelated phenomenona. A tidal wave is a shallow water wave caused by the gravitational interactions between the Sun, Moon, and Earth. A tsunami is a sea wave caused by an underwater earthquake or landslide (usually triggered…
Is there a relationship between large earthquakes (>M 6) that occur along major fault zones and nearby volcanic eruptions?
Sometimes, yes. A few historic large regional earthquakes (>M 6) are considered by scientists to be related to a subsequent eruption or to some type of unrest at a nearby volcano. The exact triggering mechanism for these historic examples is not well understood, but the volcanic activity probably…
What was the extent of ash deposition from the largest Yellowstone eruptions?
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…
How Hot Is A Volcano?
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…
Why are there glaciers?
Glaciers form where more snow falls than melts over a period of years, compacts into ice, and becomes thick enough to begin to move. That is, a snow patch becomes a glacier when the deepest layers begin to deform due to the weight of the overlying snow and ice.
I've noticed the little registered trademark symbol in "The National Atlas of the United States of America®." Does this mean that there are restrictions on using National Atlas data and maps?
No, not usually. Nearly all information collected by the Federal Government is in the public domain and use of raw data produced under this project is not restricted in any way. Both "National Atlas of the United States ® " and "The National Atlas of the United States of America ®…