<p>The 15 January 2022 eruption of the submarine Hunga Tonga-Hunga Ha'apai (HTHH) volcano (Tonga) ranks among the largest volcanic explosions of the satellite remote sensing era, and perhaps the last century. It shares many characteristics with the 1883 Krakatau eruption (Indonesia), including atmospheric pressure waves and tsunamis, and the phreatomagmatic interaction of magma and seawater likely played a major role in the dynamics of both events. A portion of the HTHH eruption column rose to lower mesospheric altitudes (~55 km) and the umbrella cloud extent (~500 km diameter at ~30-35 km altitude) rivalled that of the 1991 Pinatubo eruption, indicative of very high mass eruption rates. However, sulfur dioxide (SO<sub>2</sub>) emissions measured in the HTHH volcanic cloud (~0.4 Tg) were significantly lower than the post-Pinatubo SO<sub>2</sub> loading (~10–15 Tg SO<sub>2</sub>), and on this basis we would expect minimal climate impacts from the HTHH event. Yet, in the aftermath of the eruption satellite observations show a persistent stratospheric aerosol layer with the characteristics of sulfate aerosol, along with a large stratospheric water vapor anomaly. At the time of writing, the origin, composition and eventual impacts of this stratospheric gas and aerosol veil are unclear. We present the preliminary results of a multi-disciplinary approach to understanding the HTHH eruption, including 1D- and 3D-modeling of the eruption column coupled to a 3D atmospheric general circulation model (NASA’s GEOS-5 model), volatile mass balance considerations involving potential magmatic, seawater and atmospheric volatile and aerosol sources, and an extensive suite of satellite observations. Analysis of the HTHH eruption will provide new insight into the dynamics and atmospheric impacts of large, shallow submarine eruptions. Such eruptions have likely occurred throughout Earth’s history but have never been observed with modern instrumentation.</p>

We examined 2947 basalt and volcanic glass artifacts from 38 sites in leeward Kohala. Nondestructive energy‐dispersive X‐ray fluorescence provided initial geochemical characterizations. Wavelength‐dispersive X‐ray fluorescence (WDXRF) and thermal ionization mass spectrometry (TIMS) analyses were completed on samples from ambiguously sourced groups. No more than 13.9% of the probable and definite adze‐related debitage originated in leeward Kohala. Notably absent are lithic materials from the nearby Pololū Adze Quarry in windward Kohala. Material from the more distant Mauna Kea Adze Quarry accounts for 41.6% of the adze debitage. Another 38.8% of the adze debitage matches with a tholeiitic source or sources long assumed to be Kīlauea Volcano in Kaʻū, but WDXRF and TIMS isotopic data do not support a Kīlauea source. Centralized adze production and distribution networks best explain adze distribution. Scoria abraders appear to have been regularly transported from the Kona district to leeward Kohala. Volcanic glass sources loosely align with distance‐decay trends, but show greater reliance on Puʻuwaʻawaʻa material by 1650 CE.