“The ocean is on fire again”: a mud volcano explodes, illuminating the Caspian Sea

A blast of explosive fire, believed to be caused by a mud volcano, lit up the Caspian Sea on Sunday according to an APA report, an Azerbaijani news agency. The fire occurred about 10 kilometers from the Umid gas field, south of Baku, the Azerbaijani capital.

The National Oil Company of the Republic of Azerbaijan (SOCAR) told APA that none of its oil platforms were affected by the incident. No injuries were reported.

“There have been no accidents on offshore platforms and industrial facilities under the direct control of SOCAR, and work is continuing normally,” said Ibrahim Ahmadov, deputy head of the public relations and events department. SOCAR, talk to APA.

This is the second time in two days that a fiery water incident has been detailed. 2nd of July an undersea pipeline spilling gas into the Gulf of Mexico ignited the ocean surface spiraling out social media with proclamations that “the ocean is on fire”. Sunday “the ocean is on fire again” echoed throughout the Twittersphere. (The Caspian Sea is an inland sea so … okay, let’s not go into that.)

This explosion seems natural. Speaking to the APA, Azerbaijani seismologist Gurban Yetirmishli suggests the fire is indicative of a mud volcano. It wouldn’t be a surprise: the area is home to hundreds of mud volcanoes.

“Azerbaijan has basically the perfect geological conditions for mud volcanoes,” said Mark Tingay, a geophysicist at the University of Adelaide in Australia, who has meticulously recorded the location of mud volcanoes around the world.

As their more familiar and lava-filled cousins, sometimes mud volcanoes erupt. But what are they and how can they catch fire?

What is a mud volcano?

A mud volcano is exactly as the name suggests: a volcano that erupts with muddy fluids rather than lava. This means that they are not exactly real volcanoes (but let’s not get into this debate).

They are caused by water heated deep in the Earth and mixing with rocks and minerals to create sludge which is then forced to the surface via cracks or fissures. Tingay explains in a full Twitter feed from 2019 they can range from “cute little items” measuring a few inches in diameter to “huge things that are several hundred feet high and several miles wide”.

If they are near something like an oil field, they could be “hooked up” to oil and natural gas systems. When they explode, oil and gas – flammable substances – spurt up into the sky along with the mud. It’s unclear exactly how they might ignite, but the change in pressure or sparks in the mud caused by rocks smashing against each other in an eruption could explain the fireballs, Tingay notes.

Tingay analyzed the explosion of the Caspian Sea and speculated, based on some footage, that it could be a mud volcano known as Makarov Bank. That would have been interesting – in 1958, this mud volcano exploded, launching a fireball 500 meters into the sky.

But based on further analysis, Tingay also speculated on two other potential candidates close to the Umid oil field. The two were aligned with video footage and thermal anomalies detected by the National Oceanic and Atmospheric Administration: Ignatiy Stone Bank Mud Volcano (also known as Dashly Island) and Kumany Bank Mud Volcano.

Monday morning, confirmation came in the form of an overview:

A ship has been sent to the scene to investigate and Ahmadov, SOCAR, said “the public will be notified as soon as there is further information.”

Update July 5: Adds confirmation on Mud Volcano on Dashly Island