Attention:The NSF Public Access Repository (PAR) system and access will be unavailable from 5:00 PM ET until 8:00 PM ET on Friday, September 11 due to maintenance. We apologize for the inconvenience.


Title: NUMERICAL SIMULATION OF TSUNAMI IMPACT FROM THE 1/15/22 ERUPTION OF THE HUNGA TONGA - HUNGA HA’APAI VOLCANO
Tsunamis from volcanic ‘explosive’ eruptions are rare, with the last catastrophic event being Krakatau in 1883 (Verbeek, 1885), during which, tsunamis were generated in the far-field by pressure shock-waves and in the nearfield of the volcano, in the Sunda Straits, by several potential geological mechanisms including pyroclastic flows, ash column, and/or caldera collapse. On 1/22/55, at about 4:15 UTC, a one in 1,000 year eruption of the Hunga Tonga-Hunga Ha’a-pai Volcano (HTHHV), that had started on12/20/21, reached its paroxysm with a series of large underwater explosions, releasing enormous energy (4-18 Mt of TNT), and ejecting a large ash plume 58 km into the stratosphere. We simulate both the near- and far-field tsunami generation from the eruption, but in this paper we focus on analyzing and validating the near-field impact against field data.  more » « less
Award ID(s):
1756665
PAR ID:
10476837
Author(s) / Creator(s):
; ; ; ; ; ;
Publisher / Repository:
Coastal Engineering Proceedings, (37), management.85.
Date Published:
Journal Name:
Coastal Engineering Proceedings
Issue:
37
ISSN:
0589-087X
Page Range / eLocation ID:
85
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract. The eruption of the Hunga Tonga-Hunga Ha'apai volcano on 15 January 2022 provided a rare opportunity to understand global tsunamiimpacts of explosive volcanism and to evaluate future hazards, includingdangers from “volcanic meteotsunamis” (VMTs) induced by the atmosphericshock waves that followed the eruption. The propagation of the volcanic andmarine tsunamis was analyzed using globally distributed 1 min measurementsof air pressure and water level (WL) (from both tide gauges and deep-waterbuoys). The marine tsunami propagated primarily throughout the Pacific,reaching nearly 2 m at some locations, though most Pacific locationsrecorded maximums lower than 1 m. However, the VMT resulting from theatmospheric shock wave arrived before the marine tsunami and propagatedglobally, producing water level perturbations in the Indian Ocean, theMediterranean, and the Caribbean. The resulting water level response of manyPacific Rim gauges was amplified, likely related to wave interaction withbathymetry. The meteotsunami repeatedly boosted tsunami wave energy as itcircled the planet several times. In some locations, the VMT was amplifiedby as much as 35-fold relative to the inverse barometer due to near-Proudmanresonance and topographic effects. Thus, a meteotsunami from a largereruption (such as the Krakatoa eruption of 1883) could yield atmosphericpressure changes of 10 to 30 mb, yielding a 3–10 m near-field tsunami thatwould occur in advance of (usually) larger marine tsunami waves, posingadditional hazards to local populations. Present tsunami warning systems donot consider this threat. 
    more » « less
  2. n this study, we investigate the source of an ash layer found in sediment core VM33-116 (Lat: -2.9, Long: 148.583), located in the Bismarck Sea. Originally, this research aimed to understand the impact of volcanic ash on biological productivity and climate. However, our findings suggest that the ash layer, dated to approximately 3000–4000 years ago, is most likely from a submarine volcanic eruption similar to the Hunga Tonga eruption of 2022. The ash layer (39–42 cm) contains an unusual spherule aggregate and black foraminifera. Experimental work has related the formation of spherule aggregates to the intense lightening in the high-altitude volcanic plume (58 km) produced by submarine eruptions like Hunga Tonga.) The black foraminifera are colored by black carbon on the inside of the foraminiferal test- a feature that might imply increase biological productivity. Elemental analysis using ITRAX and XRF revealed changes in Fe/Al and Ba/Al ratios, indicating volcanic ash deposition. However, no significant spikes in productivity-related elements (e.g., P, S, or Si) were observed, suggesting minimal impact on biological productivity. Corrected radiocarbon dating and geochemical analysis points to a submarine rhyolitic volcano located about 90 km from the core site as the likely source. Other nearby volcanoes, such as Tavui and Rabaul, are too distant to account for the ash. Our findings contribute to understanding the source of volcanic ash in the region and suggest that Hunga Tonga-type underwater eruptions can leave lasting geochemical markers, even across centuries. The presence of spherule aggregates and black foraminifera provides valuable insights into the effects of such eruptions on surrounding marine sediments Further research is needed to fully understand the relationship between submarine volcanic activity and its impact on biological productivity. 
    more » « less
  3. The eruption of the Hunga Tonga–Hunga Ha’apai volcano on 15 January 2022 offered a good opportunity to explore the early impacts of tropical volcanic eruptions on stratospheric composition. Balloon-borne observations near Réunion Island revealed the unprecedented amount of water vapor injected by the volcano. The enhanced stratospheric humidity, radiative cooling, and expanded aerosol surface area in the volcanic plume created the ideal conditions for swift ozone depletion of 5% in the tropical stratosphere in just 1 week. The decrease in hydrogen chloride by 0.4 parts per million by volume (ppbv) and the increase in chlorine monoxide by 0.4 ppbv provided compelling evidence for chlorine activation within the volcanic plume. This study enhances our understanding of the effect of this unusual volcanic eruption on stratospheric chemistry and provides insights into possible chemistry changes that may occur in a changing climate. 
    more » « less
  4. Abstract On 15 January 2022, Hunga volcano erupted, creating an extensive and high-reaching umbrella cloud over the open ocean, hindering traditional isopach mapping and fallout volume estimation. In MODIS satellite imagery, ocean surface water was discolored around Hunga following the eruption, which we attribute to ash fallout from the umbrella cloud. By relating intensity of ocean discoloration to fall deposit thicknesses in the Kingdom of Tonga, we develop a methodology for estimating airfall volume over the open ocean. Ash thickness measurements from 41 locations are used to fit a linear relationship between ash thickness and ocean reflectance. This produces a minimum airfall volume estimate of$${1.8}_{-0.4}^{+0.3}$$ 1.8-0.4+0.3 km3. The whole eruption produced > 6.3 km3of uncompacted pyroclastic material on the seafloor and a caldera volume change of 6 km3DRE. Our fall estimates are consistent with the interpretation that most of the seafloor deposits were emplaced by gravity currents rather than fall deposits. Our proposed method does not account for the largest grain sizes, so is thus a minimum estimate. However, this new ocean-discoloration method provides an airfall volume estimate consistent with other independent measures of the plume and is thus effective for rapidly estimating fallout volumes in future volcanic eruptions over oceans. 
    more » « less
  5. Abstract The 15 January 2022 eruption of Hunga volcano (Kingdom of Tonga) produced the most lightning ever documented during an explosive eruption to date. This study estimates the mass of erupted tephra that may be structurally or electromagnetically affected by the lightning, based upon lightning peak current, channel length, and ash plume particle concentration. The lightning channels totaled 1.67 million m3in volume and contained 548 kg of volcanic ash at a calculated plume concentration of 0.328 g/m3. From this total, 54.8 kg of ash may display physical evidence in the form of lightning‐induced textures, such as lightning‐induced volcanic spherules, but this is an insignificant fraction of the total airfall deposit (10−8%). However, the total mass of ash exposed to magnetic flux densities exceeding Earth's ambient surface values is 2.24 × 1014 g, corresponding to just over a third (34.9%) of the calculated mass of total airfall (5.21 × 1014 g). This study reveals that even though physical evidence of volcanic lightning may be limited, ash particles will still be affected by the electromagnetic fields generated by the lightning discharge. The extent of these effects will be a function of lightning properties, ash properties, and location of the ash in relation to the discharge channel. 
    more » « less