After the Storm
By Denise OwensAfter the departure of Hurricane Irene, I was left with tons of damage and cleanup. My basement was my first concern. I couldn’t believe the amount of water I was seeing, but with the electricity off, I had to wait until the morning to actually see what was damaged.I knew my first…
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 we having so many earthquakes? Has earthquake activity been increasing? Does this mean a big one is going to hit? OR We haven't had any earthquakes in a long time; does this mean that the pressure is building up and there will be a big one?
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…
Will the oil in the Bakken Formation free us from depending on foreign oil?
The USGS does not make forecasts about the future potential of a particular resource to resolve national energy needs. It is difficult to determine if oil from the Bakken Formation, or any of the formations we have done assessments on, could offset other sources of oil. A number of logistical and…
Does the USGS monitor global warming?
Not specifically. Our charge is to understand characteristics of the earth, especially the earth's surface, that affect our Nation's land, water, and biological resources. That includes quite a bit of environmental monitoring. Other agencies, especially NOAA and NASA, are specifically funded…
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 relationship between faults and earthquakes? What happens to a fault when an earthquake occurs?
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…
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…
What is a volcano?
Volcanoes are mountains, but they are very different from other mountains; they are not formed by folding and crumpling or by uplift and erosion. Instead, volcanoes are built by the accumulation of their own eruptive products -- lava, bombs (crusted over lava blobs), ashflows , and tephra (airborne…
What type of eruption will occur if Yellowstone erupts again?
Yellowstone's volcanic and hydrothermal history suggests the potential for various kinds of eruptions in the future. The likelihood of a certain type of eruption occurring in the future can be judged by how often eruptions have occurred in the past. The most likely type of eruption would not…
What would happen if a "supervolcano" eruption occurred again at Yellowstone?
Such a giant eruption would have regional effects such as falling ash and short-term (years to decades) changes to global climate. The surrounding states of Montana, Idaho, and Wyoming would be affected, as well as other places in the United States and the world. Such eruptions usually form…
Where have amphibian declines been noted?
Scientists have documented four major 'hot spots' for amphibian declines: western North America, Central America, northeast Australia, and Puerto Rico. Researchers believe that all of these declines--most in seemingly pristine areas--have occurred since around 1980. Other areas of the world…