The world’s most powerful eruption in more than 30 years has left the Pacific Island nation of Tonga an ashy mess. The January 15 eruption of the Hunga Tonga-Hunga Haʻapai, a massive underwater volcano, has left unknown environmental consequences in its wake.
Tsunami waves hit Japan, Australia, and North and South America. People as far away as Alaska heard the acoustic waves generated by the explosion.
As for Tonga itself, people are just beginning to assess the damage. At least three people were killed by the eruption. “Much infrastructure will have been damaged and will need to be rebuilt,” said Sam Purkis of the Rosenstiel School of Marine and Atmospheric Science, as reported by Newswise. “More problematic is that atoll islands like Tonga have little land area and limited natural terrestrial resources.” Saltwater has inundated large portions of the island, possibly polluting aquifers and threatening agricultural land.
Coral reefs might also be in trouble, further straining the island’s natural resources. “Supplies of reef fish will be degraded, and much of the protein for Pacific islanders comes from the reef,” Purkis said.
The drinking water supply is especially worrisome. According to Cornell University postdoctoral research associate Adrian Hornby, ash-contaminated drinking water could cause acute and chronic health problems for Tongans. “The involvement of seawater in the eruption releases enormous amounts of volatile species, for example, chlorine, into the ash plume,” Hornby said, as reported by Newswise. “Together with gases released from the magma, this creates a cocktail that readily forms salts and acidic brines on the ash particles.”
According to Hornby, previous studies of this particular volcano show that its ash carries a remarkably high amount of salt, which might contain toxic substances like sulfur, fluorine and chlorine. “These salts get deposited with the ash and can be easily leached by rainfall, causing an immediate hazard to water quality, agriculture and the natural environment.” Tongans may have to rely on desalination and importing expensive freshwater for a prolonged time.
University of Miami professor of marine geoscience Falk Amelung says a submarine landslide probably prompted the eruption. With the overlying rock masses out of the way, the volcano could freely explode.