Graphic shows route of the pumice raft from Tonga to Australia.
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MILIEU

Vulkaan in Stille oceaan helpt het Great Barrier Reef vernieuwen

By Ninian Carter

August 25, 2020 - A vast raft of volcanic pumice stones that floated across the Pacific is helping to revitalise Australia’s embattled Great Barrier Reef.

In what seems like an unlikely chain of events, a mass of floating rocks twice the size of Manhattan spewed up from an underwater Pacific volcano and drifted westwards across the ocean to reach Australia's eastern seaboard.

Volcano F, located just north of the Vavaʻu islands in Tonga, erupted in August 2019, sending trillions of small pumice stones to the ocean surface where they were carried by currents across the Pacific. Pumice stones are formed from frothy volcanic glass filled with solidified gas bubbles, and are light enough to float.

As the rocks bobbed around in the water, they attracted marine organisms like algae, barnacles, corals, and more. These tiny hitchhikers ended up riding thousands of kilometres across the ocean, and are now helping to seed and replenish endangered Australian coral systems with new corals and other reef-building organisms.

It is not the first time this has happened – Volcano F also erupted in 2001, and activity is becoming more frequent, with the volcano expected to breach the surface in coming years and and form a new island.

Researchers are hopeful the latest pumice delivery will do some good for the Great Barrier Reef, which is beset by coral bleaching as the world’s ocean temperatures rise due to climate change.

The 2019 eruption’s pumice raft can now be found along Australia’s east coast from Townsville in Queensland to northern New South Wales – a spread of more than 1,300 kilometres.

PUBLISHED: 25/08/2020; STORY: Graphic News; PICTURES: Philipp Brandl (GEOMAR), Joshua Stevens (NASA Earth Observatory), Creative Commons
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