What is an exaple of a normal fault earthquake?

Question

a normal fault is when two plates are seperating

Answer 1

The question-asker is correct that divergent plate boundaries are characterized by normal faults. Neither the San Andreas fault (answer 1) nor the bigger faults of southern Alaska, the Andes and coastal Indonesia (answer 2) are normal faults.

"A fault is a fracture in the Earth's crust along which two blocks of the crust have slipped with respect to each other. Faults are divided into three main groups, depending on how they move. Normal faults occur in response to pulling or tension; the overlying block moves down the dip of the fault plane. Thrust (reverse) faults occur in response to squeezing or compression; the overlying block moves up the dip of the fault plane. Strike-slip (lateral) faults occur in response to either type of stress; the blocks move horizontally past one another. Most faulting along spreading zones is normal, along subduction zones is thrust, and along transform faults is strike-slip." from USGS site-How Earthquakes Happen:
http://pubs.usgs.gov/gip/earthq1/how.html

Regions that are extending have many normal faults. Some areas of active normal faults in the U.S. are the Basin and Range (including the Wasatch fault in Utah-which has had historic earthquakes) and the New Madrid area along the Mississippi River (big earthquake in early 1800s).
Reverse faults are common at convergent plate boundaries such as southern Alaska, Andes, Indonesia(see answer 2). The 1964 quake in southern Alaska was on a reverse fault.
Faults which move horizontally are known as strike-slip faults and are classified as either right-lateral (San Andreas fault ) or left-lateral. Faults which show both dip-slip and strike-slip motion are known as oblique-slip faults.
See the diagrams at the site below to see the differences between fault types.

Answer 2

The 1989 Loma Prieta earthquake -- the one that disrupted the World Series game -- was a normal fault earthquake. It was strike-slip, as are nearly all the earthquakes along the San Andreas Fault. (An exception is in the Los Angeles area where a bend in the fault causes two plates to collide; the 1992 Northridge quake was of this nature.) Generally in California, the Pacific and North American plates are sliding past each other, so the quakes are strike-slip rather than normal.

Also, referring to the detail of this question, earthquakes generally do occur at divergent (spreading) boundaries such as mid-ocean ridges; rather, they occur where two plates converge.

The 1964 Alaska earthquake is a good example of a normal fault earthquake. There, the Pacific Plate is heading north, colliding with the North American Plate on which Alaska sits.

Normal fault earthquakes are like a passenger car in a head-on collision with a "big rig" truck. More recent examples include earthquakes off Indonesia, and in the Andes Mountains. In the former case, the Indian Plate is pushing north into Asia, and in the latter, the Nazca Plate is subducting under the continental South American Plate, pushing up the Andes still higher.

Answer 3

There are certainly fault strains on the east coast. The Appalachian Mountain selection became into not formed by using super bands on massive ants, inspite of each thing. It in order that happens that this fault is a lot older, and is far less lively. that doesn't mean that is totally inactive. there became into an earthquake in Alabama basically some years in the past that, besides the fact that small, became into felt greater suitable than one hundred miles away in Georgia. It woke me up from a valid sleep.

Answer 4

The one in San Fransisco a few years ago that interrupted the World Series game.