Fault Lines in the United States

According to the United States Geological Survey (USGS), 39 out of the 50 American states are vulnerable to seismic activity in varying degrees.

Fault lines play a significant role when it comes to identification of regions vulnerable to seismic activities. Basically, a fault is a fracture or discontinuity in the rock structure, typically characterized by significant displacement. The line of intersection which marks the separation of this fault plane and the surface of the Earth is known as the 'fault line'. There are several such fault lines in the United States, which are used by the U.S. Geological Survey for earthquake forecasting as they help in determining the vulnerability of various regions to seismic movements.

Fault Lines in the USA

Every region has a government sponsored geological organization which keeps a track on various physical phenomenon happening in that particular region. In the United States, the US Geological Survey (USGS) is the premier geological body. Similarly, each of the states here have a state government sponsored geological organization, affiliated to the USGS, which keeps a track of geological alterations occurring in the region. These organizations prepare a geological map of the region, and mark all the fault lines lying there. On these geological maps, the fault lines are marked as black lines. There do exist geological maps which don't show the fault lines belonging to the buried faults. However, they do find a place in technical publications of the premier organizations dealing in geological studies. A map of the United States which shows these fault lines can tell you whether you reside in an area prone to earthquakes or not.

Major Fault Lines

One needs to have a sound knowledge about the various aspects of geology to recognize fault lines on the surface of the planet. Some fault lines, especially the ones that are on the surface of the Earth, are obvious. But then there are others which lie deep within the Earth's crust, obscured by a thick layer of soil, and you might not even realize that you have been living in a fault zone all this while. In the lengthy list of fault lines in the United States, the major ones include the New Madrid fault line, Rampo fault line, etc. More information about these, as well as other such United States fault lines is given below.

New Madrid Fault Line: The New Madrid fault line has recorded over 4000 earthquakes of various scales over the last four decades. Also referred to as the New Madrid Seismic Zone, this region is one of the most vulnerable region in the United States. Earthquakes in this region directly affect a range of states including Illinois, Missouri, Tennessee, Indiana etc.

Rampo Fault Line: The Rampo fault line runs over a distance of 187 miles, between the Appalachian Mountains and the Piedmont areas. Earthquakes in this fault line can have devastating effects on states like New York, New Jersey, and Pennsylvania.

Ridgefield Fault Line: One of the latest addition to the list is the Ridgefield fault line. It is believed that the Ridgefield fault line was formed around 250 million years ago. An Earthquake in this zone can result in severe damage to Connecticut, and the surrounding regions.

Denali Fault Line: In Alaska, the Denali fault line spans across the state right through the Alaska range, before entering Canada. The trench formed by this fault is most often filled by glaciers. A look at the satellite image, and you will realize that this fault line looks like a man-made canal in the Alaskan range.

San Andreas Fault Line: Spanning across the state of California, from Cape Mendocino to the Mexican border, the San Andreas fault line divides the state in two halves. Running parallel to the coast of the United States, San Andreas fault is prone to a number of earthquakes, thus making this region quite active in terms of seismic movements.

One has to also take a note of the fact that even though fault lines can help in determining whether the region is prone to earthquakes or not, they actually can't predict earthquakes. In any given fault line, an earthquake can occur at any point of time - right from this very moment to ten years from now.