For earthquakes, there is a lapsed time between the arrival of the
p-wave and the s-wave, because the waves travel at different speeds. The length
of this period of time determine the
distance to the epicenter.
Earthquakes create seismic waves. P waves are faster than S
waves. As the P and S waves move out from an earthquake, the P waves get ahead
of the S waves. The distance of a seismic station from an earthquake can be
determined from the time difference between the time of arrival of the first P
wave and the first S wave.
The hazards from the volcanoes include lava and pyroclastics, tephra and , lahars and climate alteration. Fertile soil and geothermal energy are beneficial results of volcanic eruptions. Much of El Salvador for example is convered with volcanic ash and this has been a fertile growing medium for coffee plants.
Answer: site of ancient continental collision oceanic crust subducting under continental crust
Explanation:
The answers that apply are;
- striped pattern
- provide evidence to seafloor spreading
Ocean ridges can be found at divergent boundaries where two plates are moving away from each other. As the magma rises to fill the void, it cools into rock and forms new crust. The iron minerals in the rocks align with the earth’s magnetic field before the rock cools. This causes the rocks in these areas of seafloor spreading to have band-like patterns. The irons align differently each number of years in relation to the flipping of the earth’s magnetic field. This phenomenon has been used to determine the ages of these rock layers.