Author Question: You are located a few dozen kilometers from a magnitude 6.0 earthquake. Describe the sequence and ... (Read 53 times)

c0205847 · **on:** Jul 13, 2018

You are located a few dozen kilometers from a magnitude 6.0 earthquake. Describe the sequence and effects that you will experience as a result of the different types of earthquake waves that will pass you.
What will be an ideal response?

Question 2

Describe some of the evidence for a major earthquake on the Cascadia fault around 1700, and the reason why the fault is considered to be extremely dangerous.
What will be an ideal response?

annierak · **Reply #1 on:** Jul 13, 2018

Answer to Question 1

ANSWER: The first effect will be a sudden jolt from the primary (P-wave) compression wave.
After a calm interval, an S-wave will produce a back and forth wiggling motion.
A surface wave will produce long rolling motions in the ground surface.

Answer to Question 2

ANSWER: Evidence includes the following:
Radiocarbon dating of peat and buried trees indicate that the material was buried within a few decades of 1700.
Damage recorded in tree rings of dead or damaged trees occurred around 1699.
There is evidence of a noticeable tsunami in Japan in early 1700 with no corresponding local earthquake.
Coastal Indians in the Pacific Northwest have oral traditions which include major tsunami effects near this time period.
Danger:
The average interval between major earthquakes in this region implies that an earthquake in the region is overdue. The region that would be affected is densely populated and would suffer catastrophic damage in a major earthquake.