Scientists Pinpoint The Origin Of That City-Sized Pumice Sheet Floating Towards Australia – IFLScience

True via the final few months, a gargantuan sheet of floating rock has been drifting all the way in which via the Southwest Pacific headed against Australia. The uncommon incidence has gathered quite a lot of media and scientific consideration because it modified into as soon as first noticed this summer, nonetheless, it remained unclear the effect the pumice raft in actuality got right here from. 

Now, a team of scientists from GEOMAR Helmholtz Centre for Ocean Review Kiel has pinpointed its origin: an vague, nameless underwater volcano staunch 50 kilometers (31 miles) northwest of the island of Vava’u in Tonga. 

“In the enviornment scientific literature, it appears to be like to be to this point finest under the number 243091 or as Volcano F”, Dr Philipp Brandl of GEOMAR, first author of the peek, mentioned in a statement.

The pumice sheet, made up of thousands and thousands of minute pumice stones, first got right here to light in early August 2019. Thanks to its porous structure, the pumice is able to switch with the drift, forming a enormous raft that stretched for up to 167 sq. kilometers (64 sq. miles) all the way in which via the ocean, around double the dimension of Ny.

“On August 9, 2019 we sailed via a pumice discipline for six to 8 hours, worthy of the time there modified into as soon as no viewed water,” Shannon Lenz, a sailor who filmed the pumice raft, explains in a YouTube description of their video uploaded on the time. “It modified into as soon as admire plowing via a discipline. We figured the pumice modified into as soon as on the least 6inches thick.”

Reporting in the Journal of Volcanology and Geothermal Review, researchers comprise managed to detect the provision of the pumice the use of freely accessible photos taken by the ESA satellite Copernicus Sentinel-2. They stumbled on determined traces of an active underwater eruption on the bottom in the Southwest Pacific that paired up perfectly with the following pumice overflow.

“The eruption traces fit exactly to Volcano F,” states Dr Brandl. “There comprise been finest two stations that recorded seismic signals of a volcanic eruption. Nonetheless, their recordsdata is per Volcano F because the origin.” 

Pumice is every so repeatedly formed when liquid lava erupts from a volcano into the ocean. Gases dissolve in the magma and invent bubbles that accumulate trapped because the rock presently cools by the chilly seawater.

The pumice raft is silent cruising and, judging by its latest spin and direction, is anticipated to hit the Expansive Barrier Reef enviornment on the pinnacle of January or starting of February 2020. As soon because it reaches this final vacation pickle, the pumice is anticipated to dump a load of marine microorganisms onto the reef that scientists imagine could presumably per chance aid to top off it. 

Remarkably, the largest deep-ocean eruption ever recorded is believed to comprise took place in 2012 staunch north of Recent Zealand on the Kermadec arc. This too persevered gargantuan portions of pumice – on moderate, 9,900 hundreds pumice modified into as soon as produced every single second – in conjunction with gigantic boulders of SUV-sized rocks.