International ocean research uncovers explosive history of the Galapagos Islands

Published 15 July 2015

JOIDES Resolution

An international team of geologists, including the University of New England’s Dr Alan Baxter, uncovers information on some of the most violent volcanic eruptions 14.5 million years ago off the Central American coast.

Dr Baxter and his colleagues have been researching the geological evolution of the Galapagos Islands and the Central America Volcanic Arc over recent years from the deck of the JOIDES Resolution, a ship operated by the international Integrated Ocean Discovery Program.

Dr Baxter explains, “we extracted a 100 metre-long vertical sample of the seabed, which gave us a record, from as far back as 16.5 million years ago, of the volcanic activity in the region of the Galapagos and the Costa Rican coast.”

The research findings, published in this July edition of Geology, suggest that volcanic activity in the area increased as a resulted of a large plume of magma beneath the earth’s crust forcing itself through a major partition in the seabed.

52.Core table

Dr Alan Baxter inspecting the rock sample

“The interaction of the magma plume and the spreading ridge produced great volumes of lava which led to these extreme volcanic eruptions. We know this because, remarkably, we found ash from these eruptions up to 450 kilometres away.”

This research provides a deeper understanding of the relationship between volcanoes and tectonic plates. Other important findings of the paper includes the observation that the eruptions of volcanic islands can be much more explosive than the geological community previously thought.

“This new information provides greater understanding of natural hazards such as volcanic activity and earthquakes, which we believe can help countries to plan and develop suitable policies,” Dr Baxter said.

The research, which can be found here, contributes to a larger international project focusing on the frequency and intensity of devastating earthquakes along the Central America coast.