Stick-slip Movements on Faults caused Vibrations during 2009 Mt. Redoubt Volcanic Eruption

Researchers, who examined the data of 2009 Mt. Redoubt eruption explained that the vibrations that occurred during the eruption were caused by numerous so-called stick-slip movements on faults more than a mile, beneath the volcano.

The Alaska’s Mt. Redoubt volcano erupted in March 2009, with unusual screaming sounds. A volcano normally makes sounds above the range of human hearing, but this particular eruption produced something audible.

Research Details
• Researchers explained that it was beyond the scope of their study to determine the cause of the quake; they theorized that it was the result of pressure building in blocked magma conduits underground.
• Blockage of conduit flow increases magma pressure, driving increasingly rapid deformation until the obstruction is breached and an explosion commences.
• The study concluded that the high-frequency harmonic tremors were recorded before other volcanic eruptions, as well as in the collision of icebergs. Usually, these tremors cannot be heard by people. In the case of the Redoubt eruption, however, the shaking was just barely audible as a hum.

Location of Mount Redoubt
Mount Redoubt is located in the Chigmit Mountains (part of the Aleutian Range) along the western shore of the Cook Inlet, an arm of the Gulf of Alaska, in Lake Clark National Park. Its elevation is 10,194 feet. The study was published in July 2013 edition of Nature Geoscience.