Eruption of Kilauea in 2018
The Eruption of Kilauea, Hawaii, in 2018 was caused by heavy precipitation in the previous months, according to researchers at the University of Miami. The rain would have infiltrated the porous rock, creating an overpressure that would have fractured the rock causing the lava surge. A plausible explanation but one that does not convince everyone.
On May 3, 2018, the Kilauea volcano, on Big Island in Hawaii, erupts and projects uninterrupted torrents of lava, forming a river 6 meters thick and several tens of meters wide. (Specifically the 2018 lower Puna eruption)
More than 2,000 people were evacuated and it was not until early August that the lava flow finally began to slow and the earthquakes that shook the summit decreased. At the end of September 2018, the lava covered 35.5 km² of earth and more than 700 houses were destroyed. Kilauea has just experienced the longest and most intense eruption in its recent history.
Eruption of Kilauea could be caused by Rainfall
Record rainfall in the months leading up to the eruption
According to a news study published April 22 in the journal Nature, this large eruption may have been caused by rain. In early 2018, the Hawaiian archipelago experienced an intense period of rainfall. During the first quarter of the year, 2.25 meters of water falls on Kilauea, or two and a half times the normal amount of rain during this period.
On the day of April 14-15, the island of Kaua’i, northeast of the volcano, even broke the United States’ record for rainfall with 1.26m of water that fell in 24 hours.
Underground pressure caused by infiltration into the porous rock of all this additional water would have caused the magma bag to fracture, leading to the volcano’s explosion. “The pressure in the basement of the volcano has multiplied by 10 in depths of 1 to 3 kilometers, to reach its highest level in almost 50 years,” says Jamie Farquharson, a volcanologist at the University of Miami and lead author of the study.
60% of eruptions occurred during the rainy season
The researchers also studied the chronology of past eruptions since 1790 and found that 60% of them occurred during the rainy season (between March and August). This study is not the first to relate precipitation and volcanic eruptions.
In 2009, researchers at the University of East Anglia (UK), for example, looked at the Soufriere Hills in Montserrat and found a peak in seismic activity within 6 to 40 hours of heavy rain.
The idea that the pressure exerted by the water that accumulates in the rock cavities can form new magmatic corridors is not absurd; This is also the basic principle of hydraulic fracturing, where pressurized fluids are injected into the subsoil to fracture the rock and release the fossil fuel.
However, stating that the rain is responsible for the Kilauea eruption is far from convincing many scientists who consider that the model established by the Nature authors is too simplistic an explanation for the eruption of Kilauea.
“Even if the water had reached the magma pocket, the pressure is still too low to make a difference, even for a volcano ready to erupt,” said Michael Manga, a geoscientist at the University of California, for example. Smithsonian magazine. “The recorded stresses are lower than those caused by the Moon’s gravitational pull. If the rain can trigger an eruption, why not the tides?
“This study also contradicts the hundreds of volcanoes around the world that have been saturated with rain throughout its history without causing it to explode,” added Janine Krippner, a volcanologist at the Smithsonian Global Volcanism Program, in the New York Times. As early as April 17, scientists at the site had alerted to a deformation of the soil and issued a warning that a new eruption could occur.
However, the possibility that external processes such as weather or rain trigger volcanic eruptions reminds us that volcanoes are part of a dynamic system on Earth. We are just beginning to understand these interactions.
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