Kīlauea Eruption Update, Day 128: April 27, 2021

According to our estimates, Kīlauea’s open lava lake surface has shrunk by nearly 25% in the past week while gas emissions have halved, all while low lava output continues. There is still liquid lava below the newly crusted areas, but the recently stagnant surface appears to have sagged as a result of cooling, degassing and compression, and now sits 7-10 ft (2-3 m) lower than the active lava surface nearby. The active lake continues to generally maintain its depth with small variations, remaining at a depth of 745 ft (227 m). Latest on Kīlauea, Eruption Day 128, Week 18: -Active lake surface shrinking continues at the time of this writing; our estimates yield reductions of ~20% in the southwest and ~5% in the northeast, thus far. -Another Deflation-Inflation cycle begins today, after completing the third leg of a triple DI over the first half of the week. Possibly related, no ooze-up flows have been observed along the lake’s perimeter, next to the crater walls, during the past 2 weeks. -SO2 measurements from April 21-25: 350 tonnes/day, 550 t/d, 300 t/d, 350 t/d, 375 t/d (USGS), “among the lowest emission rates measured during the current eruption.” The single measurement during the previous week was 950 t/d on April 14, while the previous low measurements ranged around 500-600 t/d about one month ago, at the end of March. -GPS shows continued caldera spreading, with a possible increase in the extension rate following the slow-down over the past month. Seismic activity is still within background levels, and still focused mainly below the summit and South Flank. We examine the lake shrinking through various new time-lapse productions, using web captures, monitoring data, and photos of Kīlauea's ongoing eruption available courtesy of the USGS Hawaiian Volcano Observatory. As usual, we discuss live viewer questions! https://www.youtube.com/watch?v=gICBHdg-YSM