We’re well into the second month of Kilauea volcano’s devastating eruption, and things show no sign of letting up. Now, we’re getting our very first estimate of how much molten rock has poured out of the ground so far. Kilauea has produced at least 113.5 million cubic meters of lava, which is enough to fill 45,400 Olympic swimming pools or bury Manhattan nearly seven feet deep.
That figure comes courtesy of the US Geological Survey (USGS), which released its estimate on June 7. According to Michael Poland, a USGS volcanologist who’s currently in Hawaii assisting with the response to Kilauea, the agency arrived at the number using several different methods.
“For example, we’ve been able to map the topographic change, so that helps in terms of how much [lava] has stayed on land,” Poland told Earther via email. “More recently, we’ve estimated the amount of lava in the feeder channel” which runs northeast from Fissure 8 in Leilani Estates through the community of Kapoho to the ocean.
Poland said that measuring the channel’s width and the lava’s velocity and making some assumptions about its depth from past flows gives us a pretty good initial estimate of how much lava Kilauea has layered on the Hawaiian landscape.
Volcanologist Wendy Stovall, also with the USGS, cautioned that the number is “definitely a low estimate,” in part because the flow’s thickness is higher in some places than calculations have assumed, but also because “a lot of lava has entered the ocean and been deposited below sea level” since June 6.
“We are unable to get an accurate account for that amount,” Stovall told Earther in an email.
As impressive as nearly 50,000 swimming pools worth of lava may sound, it’s worth noting that this is relatively small potatoes in geologic terms. USGS noted in a Facebook post that it’s only half the amount of lava that the nearby Mauna Loa volcano spewed during a major 1984 eruption.
For an even more direct comparison, Kilauea’s Pu‘u ‘Ō‘ō crater—which has basically been in a state of constant eruption since 1983—has leaked about four cubic kilometers of lava over the 30-year period since then, according to the USGS. The recent activity in Kilaeau’s Lower East Rift Zone has only erupted 0.11 cubic kilometers of lava, albeit over a much shorter time period.
If you want to put the eruption in a deeper time context, it looks downright shrimpy. As Concord University volcanologist Janine Krippner pointed out to Earther via Twitter direct message, the Icelandic volcano of Bárðarbunga produced the largest known eruption of the Holocene in terms of lava volume, releasing 23 cubic kilometers of molten earth. My back-of-the-envelope math says that’s about 9.5 million Olympic swimming pools.
The eruption is not small in human terms, however. As Kilauea’s lava flows blazed a new trail of destruction through Vacationland and Kapoho last week, entire neighborhoods were engulfed. By Friday, an estimated 700 homes had been destroyed, making this the most destructive eruption on U.S. soil since Mt. St Helens blew its top in 1980, according to reporting by Reuters.