Signals preceded the collapse of the Anak Krakatau volcano 🌋

In 2018, the eruption of the Anak Krakatau volcano triggered a devastating tsunami in Indonesia. A new study reveals that warning signs were detectable years before the disaster.

A team of researchers analyzed satellite data to understand the movements of the volcano before its collapse. They used a technique called InSAR to map surface deformations. This method detected a 50-foot (15-meter) slip along a fault, with periods of acceleration before the eruption.

The study, published in Geophysical Research Letters, shows that the acceleration of the slip was a precursor to the collapse. The researchers used data from three satellites, analyzed with significant computing power. This approach could be used to monitor other oceanic volcanoes.



Oceanic volcanoes can collapse catastrophically, generating tsunamis. Monitoring these phenomena is crucial for disaster prevention. Remote sensing techniques, such as InSAR, offer a promising solution for hard-to-reach areas.

The collapse of Anak Krakatau was preceded by a slow but accelerating slip. Researchers emphasize the importance of monitoring these movements to anticipate collapses. Ground-based instruments, such as GPS, are often absent in these dangerous areas.

The InSAR technique can detect changes of a few centimeters on the Earth's surface. However, it requires significant computing power and resources. Despite this, it could become an essential tool for volcano monitoring.

Researchers hope that this method can be used in near real-time to monitor active volcanoes. This could help detect signs of imminent collapse and save lives. Continuous monitoring of volcanoes is a major challenge for public safety.


The study of Anak Krakatau shows that warning signs of a collapse can be detected years in advance. Remote sensing techniques offer a new perspective for the prevention of natural disasters. Research continues to improve these methods and make them more accessible.

Why are oceanic volcanoes dangerous?

Oceanic volcanoes, like Anak Krakatau, present particular risks due to their instability. Their collapse can generate devastating tsunamis, like the one in 2018 in Indonesia.

These volcanoes often form on faults or underwater hotspots. Over time, eruptions accumulate volcanic material, increasing their size and weight. This growth can destabilize the volcano's structure.

When an oceanic volcano collapses, it causes a massive displacement of water, generating a tsunami. These waves can reach distant coasts, causing significant destruction and loss of life.

Monitoring these volcanoes is therefore crucial for disaster prevention. Remote sensing techniques, such as InSAR, offer a solution for monitoring these hard-to-reach and potentially dangerous areas.

What is the InSAR technique?

InSAR, or Interferometric Synthetic Aperture Radar, is a remote sensing method that uses radar images to measure surface deformations. It can detect changes of a few centimeters, even over large areas.

This technique relies on comparing multiple radar images taken at different times. The differences between these images reveal ground movements. InSAR is particularly useful for monitoring volcanoes, seismic faults, and landslides.

InSAR requires a large amount of data and significant computing power. Researchers often use supercomputers to process this information. Despite these limitations, InSAR is a valuable tool for geological monitoring.

Applications of InSAR are numerous, ranging from volcanic eruption forecasting to infrastructure monitoring. This technique continues to evolve, offering promising prospects for natural risk management.