Greece Seismic Crisis Update; Magma Intrusion at Santorini Volcano, Geologist Analysis

Summary

Santorini, Greece, is under a state of emergency due to an intense earthquake swarm, with nearly 8,000 tremors shaking the region. More than 70% of the island’s population has evacuated. Despite recent signs of magma movement beneath the Santorini volcano, the situation does not suggest an imminent eruption. The magma is slowly pooling in the shallow chamber, and the earthquake swarm is confirmed to be tectonic, not volcanic. The situation remains tense, but the earthquake activity appears to be decreasing, and there's no immediate risk of an explosive eruption.

Takeaways

• 😀 A state of emergency has been declared in Santorini, Greece, lasting until March 3rd, due to intense seismic activity.
• 😀 Over 8,000 earthquakes have occurred in the region in the past week, with tremors happening every 76 seconds.
• 😀 As a result of the earthquakes, over 70% of Santorini's residents have evacuated, and there have been reports of damage and landslides.
• 😀 Schools across at least 14 regional islands have been closed due to the ongoing seismic activity.
• 😀 Evidence of magma movement has been detected beneath the Santorini volcano, causing the ground to rise at a rate of 6 cm per year.
• 😀 Despite magma intrusion, there is no indication of an imminent volcanic eruption, and the current seismic swarm is tectonic in origin.
• 😀 Ground deformation was previously undetected due to short-term data, but longer-term datasets now show a weak, gradual uplift.
• 😀 The detected magma intrusion involves a smaller volume compared to past events, with only 6 million cubic meters of magma currently moving.
• 😀 Historical magma intrusions in 1994-1999 and 2011-2012 involved larger volumes (7.8 million and 21 million cubic meters, respectively), with no eruption occurring.
• 😀 The ongoing earthquake swarm is primarily tectonic, indicated by the earthquake depths, and is not associated with magmatic movement.
• 😀 While there's a possibility that the current magma intrusion triggered the earthquake swarm, this intense seismic activity is not unprecedented for the region.

Q & A

What caused the state of emergency in Santorini, Greece?

The state of emergency in Santorini, Greece, was declared due to a series of seismic activities, including nearly 8,000 earthquakes in a short period, which raised concerns about the potential volcanic risks.

What is the frequency of the earthquakes occurring in the Santorini region?

The earthquakes have been occurring at a frequency of about one every 76 seconds in the region between Santorini and Amorgos.

How has the population of Santorini been affected by the earthquake swarm?

More than 70% of Santorini's residents have evacuated the island due to the ongoing seismic activity.

What evidence was detected that suggests magma movement beneath the Santorini volcano?

Evidence of magma movement was detected in the form of ground deformation, with the ground rising at a rate of approximately 6 centimeters (2.4 inches) per year.

Does the detected magma movement indicate an imminent volcanic eruption?

No, the detected magma movement does not indicate an imminent volcanic eruption. The magma is pooling in a shallow magma chamber and is not actively intruding into the crust in a way that would trigger an eruption.

What is the volume of magma currently involved in the intrusion at Santorini?

The current magma intrusion involves approximately 6 million cubic meters of magma, which is significantly less than previous intrusions.

How does the current magma intrusion compare to previous intrusions at Santorini?

The current magma intrusion (6 million cubic meters) is smaller than previous intrusions, such as the 2011 intrusion (21 million cubic meters) and the 1994-1999 intrusion (7.8 million cubic meters).

What kind of earthquake activity is being observed in the region?

The ongoing earthquake swarm is tectonic in nature, with earthquakes occurring along fault lines and increasing in depth, which is typical of tectonic activity rather than magmatic activity.

Why is it unlikely that the current magma intrusion will lead to a volcanic eruption?

It is unlikely that the current magma intrusion will lead to an eruption because the volume of magma involved is small, and the intrusion is occurring slowly without active intrusion into the shallow crust.

What does the data suggest about the earthquake swarm's intensity over time?

The data suggests that the intensity of the earthquake swarm has decreased in the last two days, and the average magnitude of the earthquakes has also lowered, indicating the possibility that the most intense phase has passed.