Satellites and the Volcano

Sometimes an underwater volcano can do in a few hours what satellite applications outreach professionals try to do in months, or even years. Last Saturday’s massive underwater volcano explosion put satellite images on all frontpages and all social media timelines!

Here is how this appeared on BBC News:

“When an enormous underwater volcanic eruption occurred in the South Pacific near Tonga earlier this week, satellites were in position to capture what had happened.

That’s because there’s a large and growing fleet of Earth observation spacecraft overhead. Some have constant eyes on particular regions of the Earth, meaning their data is immediately available to study, while others are tasked with making follow-up observations.

All of the information these satellites gathered will aid the emergency response, and help scientists better understand the event.

There are a group of spacecraft that monitor weather systems from 36,000km (22,370 miles) above the Earth. They scan an entire hemisphere every few minutes, relaying images of what they see to the ground to inform up-to-date forecasts.

It was these meteorology satellites that recorded some of the most spectacular views of the volcano’s ash cloud as it climbed high into the sky.”

On social media many of these satellite videos went viral:

Even though this is a very remote stretch of ocean, several satellites caught the blast, from several different angles:

Very soon images from the nearby Tonga islands appeared, putting the following tsunami in a more human perspective:

And a few days later, satellites allowed us a closer look into the damage:

Followed by an Emergency Mapping Service activation of the Copernicus Emergency Response Service (EMS):

Another day later Sentinel-1 sees through the clouds that the volcanic island has all but disappeared during the eruption: