Cumbre Vieja: La Palma volcano opens the way to anticipate eruptions | Science

[ad_1]

In a sense, science got ahead of itself. On the advice of experts, the authorities had already begun to evacuate people with reduced mobility on the morning of Sunday 19, hours before a magma dam broke the crust of Cumbre Vieja. In the municipalities of La Palma that are now known because the lava has devastated them, they had been receiving informative talks about volcanoes and emergency plans for days. It happened more or less what was expected and more or less where expected, although most specialists acknowledge that when the earthquakes began, they thought it would take much longer for the lava to emerge. In early 2021, no one could predict that eruption for October. And now, in December, it is still not known how long it will last.

Volcanology is still in its infancy in the field of prediction. It is not a Spanish phenomenon; is in the process of taking a leap forward across the world. A necessary leap, since more than 800 million people live near active volcanoes. Recent crises such as the one in Kīlauea (Hawaii) in 2018 or the current one on La Palma are going to be a turning point. An opinion article published in the latest issue of the magazine Science He wonders if it is possible to anticipate these disasters with the Cumbre Vieja volcano as the protagonist. “The short-term forecast is based on technology and the recognition of patterns of the behavior of volcanoes and constant improvement as volcanologists collect more data, as in the case of the eruption of Cumbre Vieja”, explains by email the author of that text, Marc-Antoine Longpré. The prediction of volcanic eruptions has progressed enormously in recent decades and there are many success stories, remember, such as the famous 1991 eruption of Mount Pinatubo in the Philippines, the most explosive in recent decades, but not so lethal thanks to previous evacuations. .

See also  Obama tells Democrats how to win midterms in first White House return in five years

In the short term, science knew in September that there would be an eruption when a swarm of earthquakes shot to the surface. The stations throughout the island warned of the phenomenon and the eruption took only eight days to arrive. Four years earlier, when reactivation was detected under the island, science assumed that there would be an eruption sometime in the medium term. “This medium and long-term forecast is based on investigating the past behavior of individual volcanoes to calculate the probability of eruptions of different magnitudes occurring over periods of years to decades,” develops Longpré, a volcanologist at the City University of New York. .

The Cumbre Vieja volcano continues to erupt as seen from the El Time viewpoint.
The Cumbre Vieja volcano continues to erupt as seen from the El Time viewpoint.BORJA SUAREZ (Reuters)

To further improve forecasting of future eruptions, he explains, a better understanding of the architecture of magmatic systems beneath volcanoes and of the connection between what happens underground and monitoring observations on the surface is needed. As Pablo J. González, from the CSIC, points out, it is necessary “to refine the knowledge about the connectivity between different magma reservoirs under the Canary archipelago.” “It is the great stumbling block to better hit the duration of the eruption. When I finish we will have a better idea ”, he adds.

In Iceland, volcanologists were able to predict when the Bárðarbunga eruption would end: they knew the amount of magma fuel that feeds it, analyzed the rate at which the lava was flowing, and deduced how long it would take to run out. For this reason, Longpré believes that La Palma will be of great help. “The detailed observations collected in the precursor phase will be crucial in interpreting signs of volcanic reactivation in the future and in helping to forecast the timing and location of future eruptions once reactivation has begun,” he says.

The personality of the volcanoes

In this regard, the extraordinary deployment of personnel and tools on the Canary Island – satellites, drones, lava samples, the sea, seismic and geophysical data, gas emissions … – will help to understand much better how an island suddenly wakes up that seemed calm from 1971 to 2017. Carmen López (National Geographic Institute, IGN), the head of volcanic surveillance in Spain, has no doubts: “We will continue working when I finish [la erupción] because all the data we are collecting has infinite scientific potential, we are going to see more than a decade of research work that will greatly improve our knowledge of the volcanic phenomenon ”.

Researcher Teresa Ubide, from the University of Queensland (Australia), puts it this way: “In geology and volcanology, the past is the key to the future.” And until recently they did not have good data on the past. Ubide considers that the eruption of La Palma “is improving the knowledge of what is the personality of this volcano at a time when the volcanic monitoring capacity has improved exponentially in relation to previous eruptions ”. Geological phenomena can have timescales much longer than the human life scale, so there is usually no adequate perception of risk, explains the volcanologist, who studies the materials produced in past eruptions to reconstruct the internal architecture of the volcano and the processes that can lead it to erupt.

Eruption of the Philippine Pinatubo volcano in 1991.
Eruption of the Philippine Pinatubo volcano in 1991.USGS

It is not about speculations or gurus with secret recipes, but about developing the best science available to have better forecasts. For González, the key will be to come up with a recipe that incorporates all the ingredients that are now measured in a volcano, and analyzed separately, to describe how they interact and interpret what will happen next. “The problem we have in current volcanology is that surveillance is based on parameters, such as the number of earthquakes or the level of gases, but we do not have the model that integrates all these values. That is why we are sold, we do not have a model that interprets these signals ”, he laments. You can’t tell what gazpacho tastes like by counting tomatoes and weighing a bottle of oil.

In the US they are not better

“If we cannot determine the duration of the La Palma eruption, it is not because we are Spanish, but because it is a challenge for volcanology in general,” says González. In the US they are the same. Or worse. In 2017, the National Academy of Sciences published a report in which they warned that less than half of the 169 potentially active volcanoes in its territory have stations to study earthquakes in their surroundings, a key element as demonstrated in La Palma. And only in three were gas emissions studied in a stable way, the third factor that announces eruptions, along with earthquakes and the deformation of the ground by the magma that pushes from below. “There have been great improvements in conceptual models, compared to those used a few decades ago, but the volcanic scientific community is still not adequately prepared for the next major eruption,” lamented Michael Manga, from the University of California at Berkeley, and committee chair.

In that report, the best volcanologists in the country wondered what it takes to improve their predictive capacity and began by demanding more knowledge such as that collected these days on La Palma. And they aimed to create physical models that integrate all the values ​​and disciplines involved, which with the help of artificial intelligence will be able to find better patterns among the ingredients of that gazpacho. For example, a decisive factor will be to better understand how magma rises to the surface. It is something that the article of Science: According to previous studies, the more viscous the magma, the longer the rest period and the longer the pre-eruptive phase. In the Canary Islands this rule would not be being fulfilled.

Aerial photo of lava flowing from Bardarbunga volcano in southeastern Iceland in 2019.
Aerial photo of lava flowing from Bardarbunga volcano in southeastern Iceland in 2019.BERNARD MERIC (AFP)

In Ubide’s latest work, on oceanic islands, it is pointed out that magma reaches optimal properties to erupt at a depth of 10 or 15 kilometers, as in La Palma. “This knowledge is essential to interpret the geophysical signs of reactivation,” says Ubide. And he adds: “One of our current research lines consists of trying to generate this information faster, so that we can add the monitoring of volcano products and their chemical composition to the geophysical monitoring of earthquakes, gases, etc.”

Knowing in detail the composition of these magmas brings the holy grail of eruption prediction closer, says Ubide. But generally you don’t know what’s under the volcano until it emanates from their mouths. A study published this year in the journal Nature noted, based on Kīlauea observations from 2018, that magma viscosity can be identified by analyzing earthquakes. It would be one of those steps to be able to integrate phenomena in the same model. “We were able to show that with robust monitoring we can relate the pressure and stress in the duct system of a volcano to the underground movement of more viscous magma, which will allow us to better anticipate the eruption behavior of volcanoes like Kīlauea and adapt the strategies of answer in advance, ”explained study author Diana Roman of the Carnegie Institution.

The Academy report indicates that it is necessary to share much better all the disciplines that have something to contribute. “It is a multidisciplinary challenge”, points out González, “each volcanologist has his specialty and we would have to collaborate a lot with each other to be more precise. From the surveillance point of view, it is the parameter that would most interest the emergency manager if we move forward ”.

However, there are volcanoes and volcanoes. The Kīlauea is not like the Bárðarbunga, this is not like the Cumbre Vieja and La Palma is not like El Hierro, where the Tagoro arose under the sea. “To some extent, each volcano has its own personality!” Longpré sums up. And he warns: “All prediction efforts are important, but some volcanoes will continue to surprise us.”

You can write to [email protected] and follow MATTER on Facebook, Twitter e Instagram, or sign up here to receive our weekly newsletter.



[ad_2]
elpais.com

Related Posts

George Holan

George Holan is chief editor at Plainsmen Post and has articles published in many notable publications in the last decade.

Leave a Reply

Your email address will not be published.