2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Scientists have shown for the first time that a major volcanic eruption can occur due to rains: the eruption of Kilauea in 2018 was preceded by prolonged rainfall that filled the pore space of the host rock and increased pressure in the deep layers of the earth's crust, which caused seismic activity. In the future, such events may occur more often - the Earth's climate is changing, and scientists predict the occurrence of long periods of extreme precipitation in many parts of the planet. The research results are published in the journal Nature.
There is strong evidence for the impact of heavy rainfall on seismic activity. However, there was no earlier evidence that their influence could affect the deep layers of the earth's crust and provoke volcanic activity - they were considered as the causes of surface phenomena.
In 2018, the volcano Kilauea erupted in Hawaii. It was multi-stage and complex: cracks opened around the volcano in May, and in the summer there were a number of explosive eruptions, followed by the collapse of the caldera. The reasons for this seismic activity have not been established.
Jamie I. Farquharson and Falk Amelung of the University of Miami pointed out that the Kilauea eruption was preceded by anomalously heavy rain showers. They lasted 180 days and were very abundant: 1260 millimeters of precipitation fell in one day from April 14 to 15. Scientists suggested that due to their high porosity and permeability, the rocks could hold a large amount of moisture, and the increased pressure provoked a volcanic eruption.
To test their hypothesis, the specialists studied data from TRMM satellites (a mission to measure tropical rain that lasted from 1997 to 2015) and GPM (an international project on global satellite monitoring of snow and rainfall, which is currently in operation), and also conducted modeling of host rock response to sediment infiltration.
Changes in pore pressure in response to moisture penetration into a volcanic structure according to modeling data (gauge, from 1975 to 2015) and satellite data (satellite, c). a - change at a depth of 0-3 kilometers, b - at a depth below three kilometers. The color scale reflects the increase in pressure from light to dark. The letter E marks the 2018 eruption of Kilauea; c - a function of the probability of pressure changes at depths of 0-6 kilometers over time.
The authors of the study concluded that the leading factor that provoked the eruption was indeed heavy rains: they increased the pressure at depth to a critical point. The Earth's climate continues to change, and scientists predict the occurrence of long periods of extreme precipitation in many parts of the planet - the potential for the impact of rainfall on volcanic activity against this background will grow.
Volcanic activity is associated with climate change according to the principle of positive feedback: warming affects the amount of precipitation and can provoke volcanic eruptions, and volcanoes, in turn, emit large amounts of carbon dioxide into the atmosphere, which already led to warming and mass extinctions in the Mesozoic era …