Geologists Discover what Triggers Violent Volcanic Explosions

A team of brilliant geologists tossed out old theories about volcanic eruptions and discovered the root cause of catastrophic, violent volcanic eruptions.

University of Southampton researchers in the UK carefully investigated crystal cumulate nodules and their relationship to pressure and old magma. Their discovery may rewrite the textbooks concerning exactly what has triggered some of the most destructive volcanic eruptions throughout history.

The study, “Triggering of major eruptions recorded by actively forming cumulates,” was recently published in the journal Scientific Reports.

Focusing on the crystals and the link to an eruption’s explosive fury, the team chose the ominous supervolcano Las Cañadas volcanic caldera on Tenerife, in the Canary Islands. Some geophysicists and vulcanologist’s have predicted a high chance that the next major eruption of a Canary Island volcano could create a super-tsunami that could inundate a wide swath of the British Isles and wipe out much of the Eastern Seaboard of the United States. [“A Wave of Destruction Will Destroy America’s East Coast,” Ian Gurney, The Daily Express]

The danger of such catastrophic explosions is also explored in a breakthrough study conducted by Dr. Steven Ward from the Institute of Geophysics and Planetary Physics at the University of California and his colleague, Dr. Simon Day from the Department of Geological Sciences at University College in London, U.K. [“Cumbre Vieja Volcano—Potential collapse and tsunami at La Palma,Canary Islands.” PDF]

Geologic records confirm that during the past 700,000 years Las Cañadas has catastrophically erupted a minimum of eight times. According to strata samples taken from those periods, the volcano has spewed towering columns of deadly ash more than 15.5 miles high and catapulted superheated gas and rock over a region covering more than 80 miles.

The researchers determined the cause of the catastrophic eruptions are the tiny crystal nodules.

In a statement about the study reported by belljarnews.com, Dr. Rex Taylor, Senior Lecturer in Ocean and Earth Science at the University of Southampton and one of the study’s authors explained: “These nodules are special because they were ripped from the magma chamber before becoming completely solid—they were mushy, like balls of coarse wet sand. Rims of crystals in the nodules grew from a very different magma, indicating a major mixing event occurred immediately before eruption. Stirring young hot magma into older, cooler magma appears to be a common event before these explosive eruptions.

“The analysis of crystal nodules from the volcano documents the final processes and changes immediately prior to eruption—those triggering the catastrophic eruptions. The very presence of mushy nodules in the pyroclastic deposits suggests that the magma chamber empties itself during the eruption, and the chamber then collapses in on itself forming the caldera.”

The discovery and confirmation of the material that provides the triggering mechanism will assist in preparing better risk assessments for city planning and population management in areas that will be affected during future catastrophic volcanic events.

Taylor added, “Our findings will prove invaluable in future hazard and risk assessment on Tenerife and elsewhere. The scale of the eruptions we describe has the potential to cause devastation on the heavily populated island of Tenerife and major economic repercussions for the wider European community.”

Such a connection was originally hinted at by the research of subterranean lightning and its effect upon deposits of crystal quartz that showed a relation between earthquakes along known faultlines and as a triggering mechanism for volcanic eruptions.