Monitoring lava lake levels in Congo volcano

May 15, 2018, Seismological Society of America
Nyiragongo crater lava lake, Democratic Republic of Congo. Credit: Julien Barriere

Nyiragongo in the Democratic Republic of the Congo is among the world's most active volcanoes, with a persistent lava lake as one of its defining features. In a talk at the 2018 SSA Annual Meeting, Adrien Oth of the European Center for Geodynamics and Seismology discussed how he and his colleagues are using multiple methods to monitor lava lake levels at the volcano.

The researchers analyze seismic and infrasound signals generated by the volcano as well as data collected during satellite flyovers to measure Nyiragongo's level fluctuations. During the eruption in 2002, which caused a major humanitarian crisis, the lake was drained and the depth of the remaining crater was estimated between 600 and 800 meters. About four months after the eruption, the crater started filling up again. Nowadays, the inner crater floor is about 400 meters below the rim and the lava lake remains at high level.

"The lava lake level is, among other things, related to the variations of the pressure inside the magmatic system underneath Nyiragongo volcano," Oth and his colleagues explained." In that sense, the lava lake represents a window into the magmatic system, and its level fluctuations provide information on the recharge and drainage of the magmatic system, such as batches of fresh magma and/or gas, or lateral magmatic intrusions into the surrounding crust."

The different techniques used to observe the lava lake offer a more complete look at the volcano's activity, the authors said. The seismic and infrasound data, collected continuously, help researchers gauge pressure changes in . "Until very recently, very few high-quality data were available for this region," the researchers noted." Over the past few years, our consortium assisted the Goma Volcano Observatory to deploy one of the densest modern real-time telemetered monitoring systems in Africa. Combined with modern processing techniques, these newly acquired datasets provide unprecedented opportunities to investigate the behavior of this unique magmatic system."

In combination with seismic and infrasound data, the scientists are using high resolution synthetic-aperture radar (SAR) images captured by satellites passing over the to directly measure the rise and fall of the lava lake level. These images measure the length of the shadow cast by the crater's edge on the lava lake surface, which can be used to calculate the lava depth.

The observations are only one piece of the puzzle within the regional volcanic system, and "will certainly be of key importance for successful eruption forecasting in the future," said Oth and colleagues. "At this stage, however, these observations need to be first put into the larger context of the magmatic system in order to allow their proper interpretation in terms of eruptive processes."

Explore further: Hawaii volcano could be building up to big eruption: scientists

Related Stories

Recommended for you

Arctic ice sets speed limit for major ocean current

October 17, 2018

The Beaufort Gyre is an enormous, 600-mile-wide pool of swirling cold, fresh water in the Arctic Ocean, just north of Alaska and Canada. In the winter, this current is covered by a thick cap of ice. Each summer, as the ice ...

Antarctic ice shelf 'sings' as winds whip across its surface

October 16, 2018

Winds blowing across snow dunes on Antarctica's Ross Ice Shelf cause the massive ice slab's surface to vibrate, producing a near-constant set of seismic "tones" scientists could potentially use to monitor changes in the ice ...

World Heritage sites threatened by sea level rise

October 16, 2018

From Venice and the tower of Pisa to the medieval city of Rhodes, dozens of UNESCO World Heritage sites in the Mediterranean basin are deeply threatened by rising sea levels, researchers warned Tuesday.

New understanding of Mekong River incision

October 16, 2018

An international team of earth scientists has linked the establishment of the Mekong River to a period of major intensification of the Asian monsoon during the middle Miocene, about 17 million years ago, findings that supplant ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.