Scientists have now mapped the seafloor around the Hunga Tonga-Hunga Ha‘apai volcano, and as a result we have learned just how massive the January 2022 eruption was. By comparing their soundings with 2017 data, they determined that at least 9.5 km3 of material was discharged. Debris was found 80 km from the volcano, and the volcano’s caldera has been replaced by a cavern 850 m deep. More from the NIWA media release and from ABC (Australia).
A storymap from Esri’s Robert Waterman, based on Maxar satellite imagery, shows the rise and fall of Hunga Tonga and Hunga Ha‘apai from being two separate islands before a 2015 eruption combined them, through its time as an apparently stable but awkwardly compound-named single island until it got blown apart last month.
The digital elevation maps above and below show the dramatic changes at Hunga Tonga-Hunga Ha‘apai, the uppermost part of a large underwater volcano. It rises 1.8 kilometers (1.1 miles) from the seafloor, stretches 20 kilometers (12 miles) across, and is topped by a submarine caldera 5 kilometers in diameter. The island is part of the rim of the Hunga Caldera and was the only part of the edifice that stood above water.
Now all of the new land is gone, along with large chunks of the two older islands.
The Washington Post maps disasters in the United States, with a page that shows maps of flood warnings, tornadoes and hurricanes, extreme heat and cold (see above), wildfires, lightning, and earthquakes and volcanoes. In the wake of a natural disaster there’s usually someone suggesting that the victims are at fault for living in a disaster zone. The WaPost’s maps have an answer to that: “It turns out there is nowhere in the United States that is particularly insulated from everything.”
Last week new lava vents opened in the Kīlauea volcano’s eastern rift zone, with fissures destroying a number of homes in the Leilani Estates subdivision of the island of Hawai‘i’s Puna District. Here are some maps.
The Washington Post’s coverage is typically first rate, its maps providing both detailed coverage and context: start there. More detailed maps come from the Kīlauea section of the USGS’s Volcano Hazards Program website, with fissure maps of the entire eastern rift zone (see above) and thermal maps of the Leilani Estates fissures receiving daily or near-daily updates.
The eruption was preceded and accompanied by a number of earthquakes; NOAA has created an animated map showing the incidence, magnitude and depth of the earthquakes that took place during the week of the eruption.
The Smithonian’s Earthquakes, Eruptions and Emissions interactive map “is a time-lapse animation of volcanic eruptions and earthquakes since 1960. It also shows volcanic gas emissions (sulfur dioxide, SO2) since 1978 — the first year satellites were available to provide global monitoring of SO2.” [Axis Maps]