Fault lines in the East are not as apparent or as active as in the West, but certain stresses can lead to a rupture. Tuesday's East Coast Earthquake was the biggest in 100 years.
The 3.8-magnitude earthquake in Indiana that rattled residents – OK, maybe some teacups – hit one of the seismically quietest parts of the country.
Natural steam vents turn a what would otherwise be a bleak subarctic island into a land of bananas. Too many bananas, in fact.
Scientists have found a hydrothermal vent community three miles beneath the sea near the Cayman Islands. Other vents have led to the discovery of new and exotic creatures.
Since the 1970s, Iceland has gone from relying on imported coal for 75 percent of its energy to getting more than 82 percent of its energy from geothermal and hydro power.