Tag Archive for: Science Daily

A University of Wyoming researcher and his team discovered that weathering of subsurface rock in the Southern Sierra Nevada Mountains of California occurs due more to rocks expanding than from chemical decomposition, as previously thought.

Porosity, the void space in rock, was conventionally thought to be produced when water flows through the rock, thus resulting in minerals chemically dissolving. Because mountain watershed provides large reservoirs of water, the new findings are relevant to water resource management throughout the U.S.

The unusual event prompted U.S. Geological Survey researcher Emily Montgomery-Brown and her colleagues to look back through 33 years of seismic and water records for the region. They found that rates of shallow seismicity were about 37 times higher during very wet periods versus dry periods. Although scientists have linked earthquakes to heavy rainfall or heavy runoff before this, the evidence connecting the two has been relatively weak or ambiguous, says Montgomery-Brown. In the Long Valley Caldera case, she says, “we’re seeing phenomenal correlation between the seismicity and the stream discharge, and we are seeing about 37 times the number of earthquakes during the wet season as during the dry season.”