HUNGA-TONGA-HUNGA-HA’PAI VOLCANIC ERUPTION/EXPLOSION AND TSUNAMIS OF 14-15 JANUARY 2022 – Overview and Analysis

• Published in: Science of Tsunami Hazards
• Main Author: George Pararas-Carayannis
• Format: Article
• Language: English
• Published: Tsunami Society International 2022-08-01
• Subjects: volcanic eruptions; tsunamis; pacific tsunami 2022
• Online Access: http://tsunamisociety.org/413Pararas-Carayannis.pdf

The explosive eruption/collapse of the submarine portion of the volcano Hunga-Tonga- Hunga-Ha'apai (HT-HH) on the Tonga Kermadec volcanic arc in the southwest Pacific on 15 January 2022 occurred at the end of many weeks of activity. It was a truly global event, as was the 1883 explosive eruption/collapse of the volcano of Krakatau in Indonesia and the 1490 BC explosion, caldera and flanc collapses of the Santorin volcano in the Aegean Sea, both generating destructive tsunamis. The eruption of HT-HH was a combination of a major submarine Surtsean (phreatomagmatic) and of a subsequent ultra-Plinian atmospheric explosion which generated a very damaging local tsunami by the crustal displacements of the volcano’s caldera and flanc collapses, but also an atmospheric paroxysmal explosion similar to that of theKrakatauevent. Inrecentyears,thedevelopmentofnewinstrumentationandofanexpanded array of terrestrial and space instruments - including atmospheric pressure sensors, seismometers and a fleet of satellites monitoring the Earth across the entire spectrum of light – provided better global monitoring of the effects of this particular and unusual 2022 Hunga-Tonga volcanic event. Specifically detected were concentric atmospheric gravity waves, which also resulted in unusually-traveling ionospheric disturbances (CTIDs) – mapped on both of the earth’s northern and southern hemispheres along conductive magnetic field lines, and which circled the earth three or four times many hours after the eruption/explosion. In addition to local destructive tsunami generation in the immediate area and elsewhere in the Paciific, the violent eruption created an impulsive Lamb wave propagation on the surface air pressure which, moving near the speed of sound at ∼340 m., traveled faster than sea surface tsunami wave(s) and was observed globally - reaching Japan, Australia, Central and South America and elsewhere. Tsunami-like waves were observed or recorded, particularly along coastal areas of Central and South America. The present study provides an overview, an analysis and a brief comparison with past volcanic events and of their different tsunami generation mechanisms, as well as a brief description of the recorded atmospherically-generated waves and disturbances following the eruption/collapse of the HT-HH volcano.