What is the scale we use to measure the strength of an earthquake? Tuesday, February 7 What is the scale we use to measure the strength of an earthquake?

What is the largest earthquake ever? May 22, 1960 in Chili. 9.5 magnitude earthquake. Biggest in the 20th century, since we can actually measure them. Most people were killed by a tsunami that traveled 200 mph.

Top 10 Recorded Earthquakes in modern time

Sumatra, Indonesia December 26, 2004 Magnitude 9.1

Fukushima, Japan March 11, 2011 9.1 on Richter

Earthquake facts: The biggest in Utah? Since settlement in 1847, Utah's largest earthquakes were the 1934 Hansel Valley earthquake, north of the Great Salt Lake, magnitude 6.6, and the 1901 earthquake near the town of Richfield, estimated magnitude 6.5. About 700earthquakes (including aftershocks) are located in theUtah region each year.

 The big one (that has yet to strike). According to Professor Bart Kowallis of the Department of Geological Sciences at Brigham Young University, there are 10 fault segments running along the Wasatch Fault. Each fault segment has been trenched and dated with Carbon-14 analysis to reveal 3-4 events on each segment. Surveys of each segment indicate one big earthquake about every 500-2000 years. Analysis of all fault segments running through the Wasatch Front suggests the chance of a major earthquake event on any fault to be one every 200 years on average. Almost all of the segments of the faults have had a major earthquake within the last 500 years. There are two exceptions: the Salt Lake segment (1000 years ago) and the Brigham City segment (over 2000 years ago). To put this in perspective, since 1971, there have been 7 major earthquakes along the San Andreas Fault in California. Perhaps Salt Lake Valley is possibly overdue for a quake after all. For now, Salt Lake Valley residents can rest a bit easier about earthquakes. Kowallis says, “We shouldn't lose sleep at night over having an earthquake in the Wasatch Front. We should more be concerned about preparing our buildings for earthquakes. Besides, a flood is much more likely to happen than an earthquake.”

April 18, 1906 7.8 Magnitude Earthquake San Francisco, CA. 3,000 people died 80% of the city was destroyed

San Andreas Fault: a strike-slip fault

Earthquake Safety Protect yourself from falling objects (GET UNDER SOMETHING) or stand in a hallway or doorway (watch out for a swinging door) Do not try to go outside during the earthquake After the earthquake and before the aftershocks, go outside Do not return to the building until it has been inspected

Interesting Facts Earthquakes rarely kill people … Building collapses do!

Interesting Facts Even buildings left standing are dangerous. There is often structural damage.

Effects of Earthquakes People are often left homeless. They must find temporary housing. Haiti Jan 2010, 7.0 magnitude