(10-01-2026, 09:48 AM)kalianna Wrote: Is anybody else awake? Lots of quakes at the summit and the tiltmeter has just risen 30+ microrad over the last couple hours. That is far more than the maximum inflate/deflate pattern weʻve seen over the last few years.
No, I wasn't watching.. am just now catching up.. what a ride. A few points..
Looking at the earthquakes it's worth noting they are all shallow, within the edifice.. all registering between 1km and -1km (where 0km is sea level). And, the northern trend makes one wonder if some sorta of widening.. a new dike maybe.. north of Halemaumau (like all those other vents) is occurring? The increase in tremor suggest some sort of mass migration of magma. But it apparently did not detract from the magma present at the vents.
Interestingly, The largest quake in the series was located right in the middle of the caldera. Right in the middle of the northern side of the rim of the current crater. This is an area where we had a fissure, with an east west strike to it, eruption in 1982, just before the onset of East Rift activity at Puu Oo.
Also worth noting, a few hours later there was a surge of eruptive activity at 00:55 at the northern vent that latest about 5 minutes. This was notably gas depleted.. no spatter, no flying lava, just a gush of melt overflowing the vent.
But all told, what does this mean? It will be very interesting to see what HVO concludes. Hopefully it will be in their update this morning.
I have always expected a change from gas rich high volume episodic fountains to continuous low level eruption effusion of lava.. a lava lake.. as the most possible end of these series of fountains. But that is just because it's a traditional scenario. But no matter, it's always fun!
ETA: HVO posted in this morning's 9:05am update here..
Increased earthquake activity began yesterday, September 30, 2026, at approximately 2 p.m. HST, underneath Halemaʻumaʻu. In the past 24 hours, there were 98 shallow earthquakes located across the summit region, primarily underneath Halemaʻumaʻu, the largest of which was a magnitude (M) 3.4 earthquake at 9:52 p.m. H.S.T. Starting around 8 p.m. HST., summit tiltmeters began to show extremely rapid changes consistent with crack growth in an east-west orientation near the current vent area, suggesting that magma was intruding in this region. Most of the seismicity was confined to the western part of Halemaʻumaʻu and the northwestern part of Kaluapele, the summit caldera. Between 8 p.m. H.S.T. last night and 3 a.m. this morning, Uēkahuna tiltmeter (UWD) recorded approximately 38.5 microradians of inflation (this value has been corrected for a spike in the signal caused by the M3.4 earthquake). Since 3 a.m. H.S.T. this morning, summit inflation has flattened out and earthquake activity has decreased. A comparison of webcam imagery before and after the intrusion does not show any new ground cracking or eruption of lava in a new location.