Carlo Doglioni, president of Ingv: “Marsili was discovered last century, it is very large and active”
There are other volcanoes in the world such as l’Hunga Tonga Hunga Ha’apai which caused the disaster of the Tonga Islands? The answer, while affirmative, is not immediate because underwater volcanoes are hidden giants, often discreet, at least until they decide. to come out of anonymity. And even when they show themselves they are difficult to monitor, as in the case of the largest underwater volcano in Europe and the Mediterranean area, the Marsili, which is located on the axis between Palermo and Naples and was only discovered between the two wars. world cup. «On Earth», explains the Lincei academician and president of the National Institute of Geophysics and Volcanology (Ingv), Carlo Doglioni, «there are always on average 40-50 active volcanoes. We do not yet have direct and widespread information on underwater active volcanoes, especially if they do not emerge from sea level with explosive or effusive material. We know that the bottom of the Pacific Ocean is dotted with thousands of volcanoes, but we only know a small part of them. The submarine volcanoes on the western side of the Pacific are linked to subduction, the descent of the lithosphere, the outer shell of the Earth about 100 km thick, inside the Earth’s mantle ».
–
For NASA, the explosion of the volcano was 500 times more powerful than Hiroshima. How do you arrive at the estimate?
«Earthquakes are classified according to their magnitude: the greater the magnitude, the higher the energy released, the greater and longer the shaking of the ground and therefore the consequent damage. Eruptions can instead be classified according to the volumes that are erupted through the Volcanic Explosive Index (VEI) which quantifies the volumes emitted during the eruption. The eruption of Hunga Tonga Hunga Ha’apai last January 15 had a VEI of about 5, ie between 1 and 10 cubic km of pyroclastic material and lava. As a reference, the eruption of the Indonesian volcano Tambora in 1815 had a VEI 7, ie with over 100 cubic km of expelled material ».
–
And the Marsili in the Tyrrhenian Sea? What is his condition?
“In Japan, there are about one hundred active volcanoes linked to subduction. In Italy we have ten volcanoes that we consider active. Marsili is a very large volcano, but we don’t have one submarine monitoring systemor that allows us to fully understand its activity, and not even the level of explosiveness which depends precisely on the chemistry of its magmas. However, we have several subaerial volcanoes for which we must pay the utmost attention, especially those related to subduction because they are more explosive, such as Vesuvius, Campi Flegrei, Ischia, Stromboli and Vulcano. For those submarines, such as Palinuro and others, the Ingv is continually engaged in campaigns for their better surveillance ».
–
Is there a relationship between climate change and Earth’s geological events?
“The eruptions of Tambora or Krakatoa (1883) brought sulfur dioxide and ashes into the stratosphere, that is, over 10-20 km in height, that level of the atmosphere where there are no clouds and rain capable of bringing volcanic emissions to the ground : an aerosol is thus formed which disperses a sort of fog around the globe which retains a small part of the radiation, just enough to slightly decrease the temperature of the globe. In the 15 months following the eruption of Pinatubo in 1991, an average decrease in global temperature of about 0.6 degrees centigrade was measured. So, yes, volcanoes can certainly change the climate and in the history of the Earth this has happened many times. In the Cretaceous period, between 145 and 66 million years ago, terrestrial volcanism was particularly intense and an interpretation of the great mass extinction at the end of this period (including dinosaurs) can be interpreted as an effect of the consequent cooling of the atmosphere terrestrial. However, the eruptions we are experiencing are ephemeral and let us not delude ourselves that they are able to counteract the global warming we are experiencing as a consequence of the anthropogenic emission of greenhouse gases into the atmosphere ».
–
January 19, 2022 (change January 19, 2022 | 21:38)
© REPRODUCTION RESERVED
–
—
