Hawaiian Volcano Update: Kīlauea Summit Still Swells, July 18, 2024

Six weeks since its Southwest Rift eruption and two weeks since its heightened Upper East Rift earthquake swarm, Kīlauea’s summit and upper rift zones are still swollen and continue to gradually inflate with more magma accumulating underground. GPS and satellite monitoring data show the ground bulging most in the area of the South Caldera, with most of the volcano within a 5-mile radius showing measurable uplift. Earthquakes this past week were most active on the Upper East Rift as well as clustering in the South Caldera, but with numbers still well below those registered in the recent swarm. The prognosis from the USGS Hawaiian Volcano Observatory remains unchanged where, “substantial increases in seismicity and/or deformation could result in a new eruptive episode, but presently there are no signs of imminent eruption.”

As has become the norm, volcanic gas emissions remain the primary ongoing threat to residents and visitors, but have been measured relatively low around 100 tonnes of SO2 per day on July 17; even so, gas is still a concern for sensitive individuals nearby. Seismic activity and adjustments on the volcano are also more frequent; as always, residents should be prepared for the possibility of damaging earthquakes.

Maunaloa volcano remains quiet, continuing to recharge in the normal pattern following its 2022 eruption, and returning to its usual inflationary pace last week. Minor flank movement on Maunaloa has also been occasionally evident in response to events on Kīlauea, but with no significant long-term effect.

As our special topic today, we examine the July 19-22, 1974 summit eruption of Kīlauea on its 50-year anniversary. Similar and in nearly the same place as the August 1971 eruption, the first of three eruptions in 1974 was the result of magma build-up in the summit following the deactivation of Maunaulu. We discuss the eruption and its place in a phase where the South Caldera, Southwest Rift, and Koaʻe Fault Zone were accomodating magma in a pattern similar to today.

As usual, we review the monitoring signals, imagery, and reports available courtesy of the USGS Hawaiian Volcano Observatory, annotating the presentation on screen as we go and discussing live viewer questions. 

To support our productions please like, share and subscribe, and consider making a donation at https://hveri.org/donate .