Why So Much Volcanic Activity?
It has been an explosive spring, at least in terms of volcanoes. This month’s eruption of Volcán de Fuego in Guatemala killed scores of people with hundreds still missing. Hawaii’s Kilauea volcano has been erupting since early May, spewing lava and poisonous gases and triggering earthquakes.
To understand more about the causes and consequences of the eruptions, The Graduate Center turned to one of our own volcanologists — Professor Marc-Antoine Longpré (GC/Queens, Earth and Environmental Sciences).
His research includes reconstructing eruptive histories of volcanoes and analyzing the chemical composition of volcanic rocks to understand eruption processes.
Professor Marc-Antoine Longpré
A college trip to Ecuador set him on his path. “I set foot on a volcano for the first time — and it was breathtaking,” he recalls. “That was it. I was hooked, and I began doing research projects in volcanology as an undergraduate student and never stopped.”
Here, he answers our questions.
GC: What caused the Hawaii and Guatemala eruptions?
Longpré: Kilauea [Hawaii] and Fuego [Guatemala] are very different volcanoes producing very different eruptions. Kilauea is more or less continuously fed by magma coming from a thermal anomaly in the earth’s mantle. The current fissure eruption at Leilani Estates and Lanipuna Gardens was caused by migration of magma from under the center of the volcano to its east flank, the so-called east rift zone. Volcanism at Fuego, and other Central American volcanoes, is due to “subduction,” a process by which one tectonic plate (here, the Cocos Plate) is shoved under another (the Caribbean Plate). Fluids released from the down-going plate cause the generation of magma that feeds the volcanoes. Fuego is frequently active, but the June 3, 2018, eruption was significantly larger than other recent eruptions. An unusually large pressure buildup, or perhaps a rapid influx of new magma from depth, may have caused this explosion, but it is hard to say at this stage.
GC: Volcán de Fuego is in the Ring of Fire. Are we likely to see other significant activity — either earthquakes or volcanic eruptions — this year?
Longpré: Yes, but not necessarily related to what we’re seeing at Fuego right now. There is always significant seismic and volcanic activity along the Ring of Fire each year, but whether we hear about it on the news depends on the magnitude and impact of this activity.
GC: Volcanologists seem confident that the Kilauea eruption will remain predictable and manageable. Do you agree?
Longpré: Yes, but this doesn’t mean there cannot be surprises. Kilauea is extremely well studied, and we know quite precisely what sort of behavior it had in the past. For example, the current fissure eruption on the east rift zone and simultaneous explosive activity at the volcano’s summit reproduce a scenario very similar to that of the 1959–1960 eruption. In addition, a myriad of instruments, particularly precise GPS and seismometers, constantly take the pulse of the volcano, which allows us to “see” where the magma is headed underground.
GC: Will the Kilauea or Volcán de Fuego eruption have any effect on climate change? What are the other potential environmental threats?
Longpré: These eruptions are unlikely to be felt by the climate system. The Kilauea eruption does release significant SO2 or sulfur dioxide, but it is not powerful enough to inject this gas into the stratosphere where it could cool the earth a bit. The Fuego eruption, though devastating, was likely too small to have any climate impact. Local impacts could include acid rain and ash-related hazards.
GC: What can volcanologists learn from the eruptions in Hawaii and Guatemala?
Longpré: From closely monitoring the Kilauea eruption, volcanologists will learn a lot, and it will take several years to analyze the wealth of data that have been collected. I expect there will be groundbreaking findings on architecture of the “magma plumbing system” of the volcano and how it operates. Ultimately, the observations at both Kilauea and Fuego will help better predict the nature of their eruptions in the future.
GC: Have you witnessed an exploding volcano? If so, what was it like?
Longpré: Yes, I have seen several volcanoes erupt, most notably Piton de la Fournaise [Réunion Island], Masaya [Nicaragua], Sakurajima [Japan], and Colima [Mexico]. Each time I felt extremely excited but also quite humbled by the power of nature, which we must never underestimate.
Submitted on: JUN 19, 2018
Category: Earth and Environmental Sciences | Faculty | General GC News