Keith Putirka earns international attention for volcano research

Keith Putirka

Dr. Keith Putirka, a Fresno State professor of earth and environmental sciences, is sparking a reconsideration of how volcanoes are formed.

Putirka, along with professor Christopher Condit of the University of Massachusetts, Amherst, are proponents of a new theory about how magma makes its way to the surface of the earth to form volcanoes.

Their research was featured in article in the Aug. 16 edition of “The Economist" magazine. The historic magazine, published in the United Kingdom, has a circulation over 830,000, more than four-fifths of it outside Britain.

The traditional scientific view of volcano formation saw a large pool of magma, or molten rock, deep beneath the earth surface that erupts through a volcanic vent to the surface. Putirka and Condit’s new model sees a far more complex structure, a massive network of magma-filled cracks the scientists describe as a “magma-mush,” moving a column of magma to the surface.

The two professors are building a case for the new volcano formation model by tracing the incidence of a mineral called clinopyroxene. The varying presence of the mineral enables the scientists to determine exactly how deep magma was formed. They have been studying the Springerville volcanic field in Arizona to track how magma has changed chemically as it traveled up to the surface.

At Springerville, “The Economist” reports, Putirka and Condit discovered two levels in the crust where magma had paused and pooled before bursting through to the surface. One pool was in the middle of the crust, while the second was much closer to the surface. They found no evidence that the magma came from the base of the crust, suggesting that the old model for volcano creation was wrong, at least in the Arizona field.

The Economist notes that scientists believe the new model of volcano formation may allow better predictions of eruptions, and explain why some volcanoes explode violently and others simply ooze molten lava at the surface.

Putirka and Condit are continuing their studies at other volcanically active areas.