Maunaloa Update, April 23, 2021: Another week, another earthquake swarm

For the 3rd consecutive week, an earthquake swarm has occurred on dormant Maunaloa. However, in between the earthquake clusters, seismic activity has decayed back to the elevated background levels typical of 2021. This pattern suggests that while the volcano continues filling, its flanks are still able to incrementally adjust to accommodate the increasing volume of magma within. Notable recent seismicity & deformation on Maunaloa: Apr 16-17 Seismic swarm northwest of summit, M3.2 and ~50 less than M2 Apr 8-11 Seismic swarm northwest of summit, M2.4 largest of 150 events Apr 3 M3.9 and M4.3 on south flank near Pāhala Mar 29-31 Seismic swarm northwest of summit, M2.7 largest of 172 events Mar 18 Seismic swarm east of summit in upper Kaʻōiki, M3.5, more than 40 eqs Mar 18-Apr 7 Summit contraction (GPS), largest in 5 years of ~15mm Mar 10 M4.2 on southeast flank below lower Kaʻōiki Mar 6 M3.2 in caldera, near surface Overall earthquake totals below Maunaloa are down (slightly) to 175 over the past week, still mostly below the summit and upper elevation flanks. During the past week, the GPS distance cross the summit continued to slowly extend, after switching from contraction the week prior. Ground tilt, gas emissions and fumarole temperatures remain stable. We summarize the recent monitoring and seismicity through a variety of plots and animations courtesy of the USGS Hawaiian Volcano Observatory and IRIS. As usual, we address live viewer questions. https://youtu.be/9EdtOwjAQac