Home Reef Volcano Grows


Dry land is ephemeral at Home Reef, a mid-ocean volcano in the central Tonga islands. 

Dry land is ephemeral at Home Reef, a mid-ocean volcano in the central Tonga islands. Cycles of eruptions and erosion have periodically created and destroyed a small island there since at least the mid-19th century. In June 2024, an eruption tacked on new area to the speck of land, lofted a volcanic plume into the sky, and discolored the surrounding seawater.

Volcanic activity at Home Reef is on display in this image, acquired by the OLI-2 (Operational Land Imager-2) on Landsat 9 on June 15, 2024. On that day, lava flowed from a vent on the island, according to Tonga Geological Services, expanding the land that emerged in a September 2022 eruption and causing the coastline to bulge out to the east.

As a cloud of volcanic emissions streamed west, a plume of discolored water flowed east and south, its lighter color contrasting with the blue seawater. Previous research has shown such plumes of superheated, acidic water can contain particulate matter, volcanic rock fragments, and sulfur, as well as precipitates of silicon, iron, and aluminum oxides. At other submarine volcanoes, scientists have detected a change in water color via satellite imagery up to one month before an eruption, suggesting that ocean color could presage a potentially destructive event.

Read more at NASA Earth Observatory

Image: NASA Earth Observatory image by Lauren Dauphin, using Landsat data from the U.S. Geological Survey.