Surprise magma chamber found under Mediterranean volcano near popular tourist destination
A new study has uncovered a previously unnoticed magma chamber beneath Kolumbo, a active submarine volcano in the Mediterranean Sea near Santorini, Greece.
A group of international researchers used a new volcano imaging technique that produces high-resolution images of seismic wave properties, according to a Jan. 12 release from the American Geophysical Union (AGU).
The study was published in the AGU journal Geochemistry, Geophysics, Geosystems, and the authors noted that the chamber’s presence “poses a serious hazard because it could trigger a highly explosive, tsunamigenic eruption in the near future.”
Researchers are recommending real-time hazard monitoring stations near other active submarine volcanoes to improve estimates of when an eruption is likely to occur.
“The current state of the reservoir indicates that an explosive eruption with major societal impact is possible (although not imminent) in the future, so we propose establishing a permanent observatory with continuous monitoring of earthquakes… and seafloor geodesy” , they wrote.
The indicated eruption would be similar to, but of a smaller size than the recent one Hunga Tonga-Hunga Ha’apai eruptionwith a predicted tsunami and an eruption column tens of kilometers high.
The study was reportedly the first to use full-waveform inversion seismic imaging to look for changes in magmatic activity below the surface of submarine volcanoes along the Hellenic Arc, where the volcano is located.
The technology is applied to seismic profiles, or ground motion recordings along miles of lines, and assesses differences in wave speeds that may indicate subsurface anomalies. The group found that full waveform inversion technology can be used in volcanic regions to find potential locations, sizes and melt rates of mobile magma bodies.
The seismic profiles were constructed after the scientists fired aerial gunfire from a research vessel passing over the volcanic area, creating seismic waves that were recorded by seismometers on the ocean floor along the arc.
A significantly reduced speed of seismic waves traveling under the seafloor indicated the presence of a mobile magma chamber beneath Kolumbo, according to the study, with the characteristics of the wave anomalies used to better understand the potential hazards the magma chamber may pose.
Images helped identify a large magma chamber that has since grown at an average rate of about 4 million cubic meters per year Columbo’s last eruption in 1650 CEalmost 400 years ago.
It was the last time Kolumbo erupted killed 70 people in Santorini.
The study’s lead author noted that if the magma chamber’s current growth rate continues, the volcano could reach the melt volume of 2 cubic kilometers estimated to be ejected during the 1650 CE eruption sometime in the next 150 years.
While volcanic melt volumes can be estimated, there’s no way to say for sure when Kolumbo, which lies about 500 meters deep, will erupt next.
“We need better data on what’s really underneath these volcanoes,” Kajetan Chrapkiewicz, a geophysicist at Imperial College London and the study’s lead author, said in a statement. “Continuous monitoring systems would allow us to better estimate when an eruption might occur. With these systems, we would probably know about an eruption a few days before it happens, and people could evacuate and stay safe. “
In recent years, scientists have been working to establish SANTORY (Santorini’s seafloor volcanic observatory) that can measure the progress of the volcanic activity of Kolumbo. It is still under development.
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