Scientists who have been listening to underwater microphones off of the coast of Oregon have found an unusual number of earthquakes. This usually occurs before a volcanic eruption. Too bad there are no volcanoes nearby. Scientists do not understand what the earthquakes signify, but they could be the result of magma rumbling away from the recognized earthquake faults off of the Oregon coast.
How Earthquakes Work
There have been more than 600 quakes over the past 10 days. The largest earthquake measured at 5.4 on the Richter scale, but the rest were below 5. On the hydrophones, the quakes sound like rumbling thunder far away. Some of the earthquakes have also been detected by seismographs on land.
The Earth’s crust is made up of plates that rest on molten rock, which are constantly rubbing together and butting up against each other. When these plates ram into each other and slip, earthquakes are created. When the molten rock, or magma, erupts through the crust, it creates volcanoes. To cause these quakes, the Juan de Fuca Plate is being crushed between the Pacific Plate and North America. Scientists still wish to go out for soil samples to discover more about about the chemical activities by the quakes.