The Hunga Tonga-Hunga Ha’Apai volcano erupted last January. As all underwater volcanoes do, it ejected water vapor into the atmosphere. As do all underwater volcanoes. But in a colossal amount that amazed the researchers. So much so that they are now asking the question of the possible global consequences for the Planet and its climate.
Last January, an undersea volcano with an extended name — dubbed Hunga Tonga-Hunga Ha’Apai — erupted in the Pacific. In the process, a tsunamitsunami swept through the Tonga Islands, impacting nearly 90,000 people. The sound of this powerful eruption circled the Earth twice! At the beginning of the summer, researchers from the Jet Propulsion Laboratory (JPL, United States) taught us that the anger of the volcanovolcano also projected an absolutely colossal quantity of water vapor into the airsairs. Enough to fill nearly 60,000 Olympic swimming pools!
“We have never seen anything like it”comments Luis Millan, researcher at JPL, in a press release. “It was a once in a lifetime event”confirms Holger Voemel, researcher at National Center for Atmospheric Research (United States) and author of complementary works on the question published in September. According to their figures, it is no less than 146 teragrams, or 146 billion kilogramskilograms of water vapor that the Hunga Tonga volcano has sent directly into the stratosphere — and even a little above — the layer ofatmosphereatmosphere which is between 15 and 50 kilometers above the ground. This is almost four times more than what was ejected by the eruption of Mount Pinatubo (Philippines) in 1991. And no less than 10% of the total quantity of water vapor already present at this level of the atmosphere .
This is all the more remarkable as it remains rare for volcanic eruptionsvolcanic eruptions inject water vapor into the stratosphere. Almost 20 years since the NasaNasa take readings. And that had only happened two other times. During the event of Kasatochi (Alaska) in 2008 and during the eruption of Calbuco (Chile) in 2015. In proportions very far from being comparable, in addition. The excess water vapor had quickly dissipated. This time, it could persist for up to ten years.
Consequences for life on Earth?
Researchers attribute the phenomenon to a kind of position “ideal” from boilerboiler of the volcano some 150 meters deep. Deeper and the pressionpression of the ocean would have attenuatedattenuated the eruption. Shallower and there would have been much less superheated water to form steam.
The trouble is that the presence of water vapor in the atmosphere is not as neutral and innocent as it might seem at first sight. Because in the stratosphere, water vapor tends to produce radicals that carry electronselectrons “singles”. What makes them highly reagentsreagents. They tend to destroy theozoneozone. However, stratospheric ozone is the one that protects life from radiation ultravioletultraviolet harmful that comes to us from SoleilSoleil. But it is difficult for researchers to conclude with certainty on this subject. Knowing that they have never studied an eruption like that of the Hunga Tonga volcano. The only thing they know for sure is that they were able to measure water levels in the stratosphere using weather balloons, which usually aren’t sensitive enough for that.
Water vapor also plays a fairly direct role in the greenhouse effect. It is even a rather effective greenhouse gas. Because it can absorb radiation infraredinfrared emitted by our Earth over a wide range of frequencies. Thus, the eruption of the Hunga Tonga volcano and the massive injection of water vapor that followed should have at least a one-time effect — potentially several years all the same, once the carbon dioxide sulfursulfur refreshing dissipated — on average temperatures. Raising them a little more. However, the expected effects should remain minimal and temporary. As for possible longer-term significant consequences on anthropogenic global warming, scientists are still divided.