Volcano Minute — Scientists sample layers of Kīlauea’s past

Aloha, it's your weekly Volcano Minute, brought to you by the USGS Hawaiian Volcano Observatory.

In July of this year, scientists visited a rare window into Kīlauea volcano’s long-term history — layers of lava, ash and other tephra exposed along the western wall of Kaluapele, the summit caldera, during the dramatic 2018 collapse. Because Kīlauea is usually active, much of the surface is covered by young lava flows less than a thousand years old. That makes these older deposits especially valuable.

The 2018 collapse revealed sections of lava and tephra that hadn’t been seen in over a century, since shortly after the Hawaiian Volcano Observatory was founded in 1912. After 2018, when Halemaʻumaʻu crater was much deeper, scientists first identified these deposits in the crater wall using aerial imagery. The crater floor has slowly risen as a result of eruptions since 2018 and scientists were finally able to examine one section of tephra layers in between lava fountaining episodes. Some of these layers could be thousands of years old and represent past Kīlauea eruptions never before studied. 

Rising lava in Halema‘uma‘u has already reburied some of these exposures. Scientists will time their future visits between episodic lava fountaining activity, so that they can collect other samples before the lava flows cover them again. Each sampling opportunity offers a rare chance to understand eruptions long lost to time.

Most recently, Kīlauea erupted episode 54 of lava fountaining at the summit for 9 hours on August 25th.  Summit inflation has since resumed, indicating that another fountaining episode is possible and likely in the coming weeks.  

Mahalo for listening, I’m Katie Mulliken and this was your weekly volcano minute brought to you by the USGS Hawaiian Volcano Observatory.