Long Valley Caldera area has had a history of eruptions and earthquake swarms. Learn more with this interactive map that reveals geology, eruptions, earthquakes, and more.
VIEW the interactive in a separate tab, by clicking on "Open Resource" then scroll over named features. (Note some browsers lack the plugins for rollovers.)
IRIS may be discontinuing these interactive animations in 2020. This file is an HTML5 file that uses a browser to view.
Interactive map reveals seismology, geology, and geologic history of the midwest.
(IRIS is going to discontinue Flash animations in 2020)
This interactive map of the Basin and Range Province reveals earthquakes, faults, hazards, volcanoes, mines, and National Parks.
This interactive map of the Basin-Range Province reveals information about the youngest volcanic features associated with the region.
Over most of the last 30 million years, movement of hot mantle beneath the region caused the surface to dome up and then partially collapse under its own weight, as it pulled apart. Currently, there is very little actual stretching going on, and the small amount is concentrated on the Western and Eastern edges of the Basin and Range.
During Basin & Range extension, the plates pull apart, the mantle rises and melts due to lower pressures near the surface. The style of eruption depends on how long the magma sits in the crust and undergoes processes such as crystallization and melting and assimilation of wall rock.
As extension and uplift occur, erosion and sedimentation happen simultaneously but at slower rates. As extension slows down, erosion and sedimentation can overcome mountain building.
Simplified extension of the basin and range province as reflected in the GPS (global positioning system) stations at distant ends of the region. Tension created by movements of Earth's tectonic plates have stretched the earth's surface to the breaking point. The entire region has been pulled apart, fracturing the tectonic plates and creating large faults.
Volcano deformation can provide clues about what is happening deep below the surface. Two techniques used to monitor deformation include Tiltmeters and GPS.
Magmatic gas is the driving force of volcanic eruptions. A primary objective in gas monitoring is to determine changes in the release of certain gases from a volcano, chiefly carbon dioxide and sulfur dioxide. Such changes can be used with other monitoring information to provide eruption warnings and to improve our understanding of how volcanoes work.
Earthquake activity beneath a volcano almost always increases before an eruption because magma and volcanic gas must first force their way up through shallow underground fractures and passageways. The continuous release of seismic energy is induced by the movement of magma.
