The eruption of Mount Merapi, on Sunday, November 17, 2019 at 10:46, West Indonesia time, with an eruption column height of around 1000 meters, was caused, it is speculated, by a tectonic earthquake that occurred some time before one of the most active volcanoes in the Sleman area.
The earthquake and tsunami mitigation chief of the BMKG/HAGI, and vice president of the Earth Disaster Mitigation Division, dr. Daryono described his deep personal analysis on his Instagram account, daryonobmkg, regarding this issue.
According to Daryono, the day before the eruption of Mount Merapi, that is, on Saturday, November 16, 2019 at 02.54 local time, the BMKG recorded a tectonic earthquake in the Sleman regency, near the volcano, with a magnitude of 2.7 degrees.
The epicenter of the earthquake was located at coordinates 7.63 latitude and 110.47 east longitude on land, at a distance of 10 km south of the Merapi peak and at a depth of 6 km, very close to the Merapi peak.
Daryono revealed that the event was similar to the eruption of Merapi on October 14, 2019, which was also preceded by a series of tectonic earthquake activities in the immediate vicinity.
The activity of increasing volcanism is in fact sensitive to tectonic earthquakes. It is known that tectonic activity can in fact increase volcanic activity, provided that the volcano is "active", that is, with liquid magma and rich in gas production. Under these conditions, volcanic eruptions are easily triggered by tectonic earthquakes.
Merapi records from 2001 and 2006 show that before the eruption the activity of the tectonic earthquake also preceded.
There are similar data abroad, as evidenced by the eruption of Mount Unzen in Japan and the eruption of Mount Pinatubo in 1990, which were also triggered by a tectonic earthquake.
Tectonic earthquakes can increase stress tensions and trigger changes in gas pressure on the magma bag in the active volcano, a situation that easily triggers an eruption.
However, Daryono acknowledged that more in-depth empirical studies are needed to demonstrate the link between tectonic seismic activity and volcanic eruptions.
Source: Instagram/daryonobmkg https://www.instagram.com/p/B49cG2VHmOt/?igshid=qf2d9f2kackb