Other recent plate movement/earth wobble incidents in Oregon includes several mid-February events: Large landslides, loud booms and ground shaking, and a sinkhole to be exact.
Two large landslides – one in the Columbia River Gorge dumped about 2,000 cubic yards of rock and debris on highway I84 just 3 miles west of the Hood River, and another blocked US30 near Portland.
Loud booms and ground shaking reported by people from Lincoln to Tillamook Counties; some reported hearing a rumble, as well (No earthquakes recorded by the USGS in the area at the time.)
A 20 ft. deep sinkhole swallowed a woman and her dog in her Portland backyard.
Stratovolcanoes like Mount Hood are common in subduction zones. Some other stratovolcanoes of note include:
Mount Fuji in Japan
Mount Vesuvius in Italy, known for its destruction of Pompeii and Herculaneum in 79 AD
Krakatoa in Indonesia, best known for its catastrophic eruption in 1883
Mount St. Helens in Washington State.
Before Mount St. Helens erupted in May 1980, small earthquakes rattled the area, an indication that magma may have been moving below the volcano. A gradual build up of quake swarms saturated area seismographs for several days, during which 174 shocks of magnitude 2.6 or greater were recorded.
With regard to Mount Hood, Madin says the earthquakes are defining a fault, which means that fault is active. He also says that if it can cause a 2.3 quake, it is capable of a magnitude 6 or stronger quake. Now that geologists know there may be active fault close to Government Camp, they will keep a closer eye on it.