The geologists findings were released on September 14 in the journal Nature.
10,000 Years in a Month
Thanks to a sabbatical, a pandemic, and 780 years of melting subterranean rock, Jackson remained in the right place and time to witness the birth of Fagradalsfjall, a fissure in the lowlands of southwest Iceland that split and took off with lava in March 2021. By that time, everyone on the Reykjanes Peninsula was prepared for some type of eruption, he stated.
” The earthquake swarm was extreme,” he stated of the 50,000 or so temblors– some magnitude 4 and greater– that shook the earth for weeks and kept the majority of Icelands population on edge.
However, the sleep deprivation deserved it, and crankiness soon developed into fascination as lava bubbled up and spattered from the hole in the ground of the reasonably empty Geldingadalur area. Both scientists and visitors alike gathered to the location to see the most recent section of the Earths crust type. From the start, they were able to get close enough to sample the lava continuously, due to the lavas slow circulation and ample winds that blew the noxious gases away.
Volcanic eruption of Mount Fagradalsfjall in Iceland.
Led by Sæmundur Halldórsson at the University of Iceland, the geologists were searching for out “how deep in the mantle the magma stemmed, how far beneath the surface area it was kept before the eruption, and what was happening in the reservoir both prior to and during the eruption.” Concerns like these, though basic, are in fact a few of the biggest obstacles for those who study volcanoes. This is due to the unpredictability of the eruptions, the risk and severe conditions, and the remoteness and inaccessibility of numerous active sites.
” The presumption was that a lava chamber fills gradually gradually, and the magma ends up being well combined,” Jackson discussed. “And then it drains over the course of the eruption.” As a result of this well-defined two-step procedure, he added, those studying volcanic eruptions do not anticipate to see substantial changes in the chemical structure of the lava as it flows out of the earth.
” This is what we see at Mount Kīlauea, in Hawaii,” he stated. “Youll have eruptions that go on for years, and there will be minor modifications gradually.
” But in Iceland, there was more than a factor of 1,000 greater rates of change for key chemical indications,” Jackson continued. “In a month, the Fagradalsfjall eruption revealed more compositional variability than the Kīlauea eruptions displayed in years. The total series of chemical compositions that were tested at this eruption throughout the first-month period the entire variety that has ever appeared in southwest Iceland in the last 10,000 years.”
Night view of a volcanic eruption at Mount Fagradalsfjall in Iceland.
This variability is an outcome of subsequent batches of magma streaming into the chamber from deeper in the mantle, according to the researchers.
” Picture a lava lamp in your mind,” Jackson said. “You have a hot lightbulb at the bottom, it warms up the blob and a blob increases, cools, and then sinks. We can consider the Earths mantle– from the top of the core to under the tectonic plates– operating just like a lava lamp.” He went on to explain that as the heat triggers areas of the mantle to increase and plumes form and move buoyantly upward towards the surface area, molten rock from these plumes collects in chambers and takes shape, gases leave through the crust, and the pressure develops up until the lava finds a way to leave.
As a result of this distinct two-step process, he added, those studying volcanic eruptions do not expect to see significant changes in the chemical structure of the magma as it flows out of the earth.
“In a month, the Fagradalsfjall eruption showed more compositional variability than the Kīlauea eruptions revealed in years. The total variety of chemical structures that were sampled at this eruption over the course of the first-month period the entire range that has actually ever appeared in southwest Iceland in the last 10,000 years.”
Prior to the 2021 Fagradalsfjall eruption, the most current eruptions on Icelands Reykjanes peninsula happened eight centuries back. It is not yet clear how representative this phenomenon is of other volcanoes, or what function it plays in triggering an eruption.
Fagradalsfjall is a tuya volcano formed in the Last Glacial Period on the Reykjanes Peninsula, around 25 miles (40 km) from Reykjavík, Iceland.
” Just when I believe weve gotten near to figuring out how these volcanoes work, we get a big surprise.”– Matthew Jackson
” Just when I think weve gotten close to determining how these volcanoes work, we get a huge surprise,” he stated.
As described in the paper, what erupted for the first few weeks was the anticipated “diminished” lava type that had been accumulating in the tank, which is located about 10 miles (16 km) below the surface area. Nevertheless, by April, evidence revealed that the chamber was being charged by deeper, “enriched” type melts with a different structure. These were sourced from a different region of the upwelling mantle plume underneath Iceland. This brand-new magma had a less modified chemical structure, with a higher magnesium material and a greater proportion of carbon dioxide gas. This indicated that less gases from this deeper magma had escaped. By May, the lava that controlled the circulation was the deeper, enriched type. These rapid, severe modifications in magma composition at a plume-fed hotspot, they say, “have actually never ever previously been observed in near real-time.”
However, Jackson said that these modifications in composition might not be so rare. Its simply that chances to sample eruptions at such an early stage are not typical. For example, prior to the 2021 Fagradalsfjall eruption, the most current eruptions on Icelands Reykjanes peninsula took place eight centuries back. He presumes that this new activity signals the start of a brand-new, perhaps centuries-long volcanic cycle in southwest Iceland.
” We often dont have a record of the first phases of a lot of eruptions because these get buried by lava streams from the later phases,” he stated. This job, according to the scientists, allowed them to see for the very first time a phenomenon that was believed to be possible however had actually never ever been experienced directly.
For the scientists, this result presents a “crucial constraint” in how designs of volcanoes worldwide will be constructed. Nevertheless, it is not yet clear how representative this phenomenon is of other volcanoes, or what function it plays in setting off an eruption. For Jackson, its a pointer that the Earth still has tricks to yield.
” So when I go out to sample an old lava circulation, or when I check out or compose documents in the future,” he said, “itll constantly be on my mind: This may not be the complete story of the eruption.”
Reference: “Rapid moving of a deep magmatic source at Fagradalsfjall volcano, Iceland” by Sæmundur A. Halldórsson, Edward W. Marshall, Alberto Caracciolo, Simon Matthews, Enikő Bali, Maja B. Rasmussen, Eemu Ranta, Jóhann Gunnarsson Robin, Guðmundur H. Guðfinnsson, Olgeir Sigmarsson, John Maclennan, Matthew G. Jackson, Martin J. Whitehouse, Heejin Jeon, Quinten H. A. van der Meer, Geoffrey K. Mibei, Maarit H. Kalliokoski, Maria M. Repczynska, Rebekka Hlín Rúnarsdóttir, Gylfi Sigurðsson, Melissa Anne Pfeffer, Samuel W. Scott, Ríkey Kjartansdóttir, Barbara I. Kleine, Clive Oppenheimer, Alessandro Aiuppa, Evgenia Ilyinskaya, Marcello Bitetto, Gaetano Giudice and Andri Stefánsson, 14 September 2022, Nature.DOI: 10.1038/ s41586-022-04981-x.
Fagradalsfjall volcano in Iceland emerging at night.
Recent discoveries from Icelands Fagradalsfjall eruptions modify what we know about how volcanoes work.
Learning something that fundamentally changes how we understand our world doesnt happen extremely frequently. For University of California, Santa Barbara Earth scientist Matthew Jackson and the thousands of volcanologists across the world, such a discovery has actually simply taken place.
While tasting magma from the Fagradalsfjall volcano in Iceland, Jackson and his associates revealed a procedure far more dynamic than anybody had actually presumed in the 2 centuries that scientists have been studying volcanoes.
