More than eight months after an underwater volcano erupted near Tonga on Jan. 14, scientists are still analyzing the effects of the massive explosion, and are finding that it may have warmed the planet.
Recently, researchers estimated that the eruption of the Hunga Tonga-Hunga Haapa volcano released a staggering 50 million tons (45 million metric tons) of water vapor into the atmosphere in addition to huge amounts of ash and volcanic gases. This massive vapor injection increased the amount of moisture in the global stratosphere by about 5% and may have triggered a cycle of stratospheric cooling and surface heating — and these effects can persist for months, according to a new study.
Tonga’s eruption, which began on January 13 and peaked two days later, was the most powerful recorded on Earth in recent decades. The explosion extended for 162 miles (260 kilometers) and threw up columns of ash, steam and gas according to the National Oceanic and Atmospheric Administration (NOAA).
Large volcanic eruptions usually cool the planet by releasing sulfur dioxide into the upper layers Earthatmosphere that filters solar radiation. Particles of rock and ash can also temporarily cool the planet by blocking sunlight, according to the National Science Foundation University Corporation for Atmospheric Research. Thus, widespread and violent volcanic activity in Earth’s distant past may have contributed to global climate changecausing mass extinction millions of years ago.
On the topic: A huge underwater eruption of the Tonga volcano has been captured on stunning satellite video
Recent eruptions have also demonstrated volcanoescooling forces of the planet. In 1991, when the summit of Mount Pinatuba in the Philippines erupted, the aerosols that powerful volcanic explosion lowered global temperatures by about 0.9 degrees Fahrenheit (0.5 degrees Celsius) for at least one year, Live Science previously reported.
Tonga emitted about 441,000 tonnes (400,000 metric tons) of sulfur dioxide, about 2% of the thrown up by Mount Pinatuba during the 1991 eruption But unlike Pinatubo (and most major volcanic eruptions that occur on land), Tonga’s underwater volcanic plumes sent “significant amounts of water” into the stratosphere, the zone that extends from 31 miles (50 km) above the Earth’s surface to about 4 to 12 miles (6 to 20 km), according to the National Weather Service (NWS).
In underwater volcanoes, “underwater eruptions can derive much of their explosive energy from the interaction of water and hot magma,” which propels vast amounts of water and steam into the eruption plume, scientists write in a new study published Sept. 22 in the journal Science. Within 24 hours of the eruption, the plume extended more than 17 miles (28 km) into the atmosphere.
The researchers analyzed the amount of water in the plumes by evaluating data collected by instruments called radiosondes that were attached to weather balloons and pointed up into the volcanic plumes. As these instruments rise through the atmosphere, their sensors take measurements temperatureair pressure and relative humidity, transmitting this data to a receiver on the ground, according to NWS.
Atmospheric water vapor absorbs solar radiation and reradiates it as heat; with tens of millions of tons of Tonga’s moisture now drifting into the stratosphere, the Earth’s surface will warm, although it’s unclear how much, according to the study. But because the vapor is lighter than other volcanic aerosols and less subject to gravitational pull, it will take longer for this warming effect to dissipate, and surface warming could continue “for months to come,” the scientists said.
Previous studies of the eruption have shown that Tonga released enough water vapor to fill 58,000 Olympic-sized swimming pools, and that this huge amount of atmospheric moisture could potentially weaken the ozone layerLive Science reported earlier.
In the new study, the scientists also determined that these huge amounts of water vapor could indeed change the chemical cycles that control stratospheric ozone, “however, detailed studies will be needed to quantify the effect on ozone abundance because other chemical reactions may also play a role.”
Originally published on Live Science.
