Earthquakes

Earthquakes, volcanism, and hydrothermal features go hand in hand at Yellowstone. The underground plumbing of hot water and magmas beneath Yellowstone is influenced by the same stresses that cause earthquakes.
It isn't that simple. There is not one magnitude above which damage will occur.
There are a few historic examples of simultaneous eruptions from volcanoes or vents located within about 10 km of each other, but it's very difficult to determine whether one might have caused the other.
On May 18, 1980, at Mount St.
Yes. Crater lakes atop volcanoes are typically the most acid, with pH values as low as 0.1 (very strong acid). Normal lake waters, in contrast, have relatively neutral pH values near 7.0.
On January 19, 1968, a thermonuclear test, codenamed Faultless, took place in the Central Nevada Supplemental Test Area. The codename turned out to be a poor choice of words because a fresh fault rupture some 1200 meters long was produced.
The USGS has some great science fair ideas related to earthquakes. Find inspiration for projects on other science topics by browsing the USGS Education website.
Yes. Encounters between aircraft and clouds of volcanic ash are a serious concern.
The violent separation of gas from lava may produce rock froth called pumice.
Geothermal energy, heat energy from the earth's interior, is used to generate electricity in a variety of places throughout the world.