[ Earthwatchers ] [ Main Menu ]
97725
From: ryan, [DNS_Address]
Subject: Earthquakes raise alert for Hawaii's Kilauea volcano
URL: https://www.sfgate.com/news/article/earthquakes-raise-alert-for-hawaii-s-kilauea-18640425.php
|
Earthquakes raise alert for Hawaii's Kilauea volcano. But any eruption is unlikely to threaten homes Updated Jan 31, 2024 2:36 p.m. FILE -- This screen grab made on Sept. 10, 2023, from webcam video provided by the U.S. Geological Survey shows an eruption inside Hawaii Volcanoes National Park at the summit of Kilauea, one of the most active volcanoes in the world. A surge of earthquakes at Kilauea's summit prompted scientists to raise the alert level for the Hawaiian volcano on Wednesday, Jan. 31, 2024, but any eruption is unlikely to threaten homes. (U.S. Geological Survey via AP)AP HONOLULU (AP) — A surge of earthquakes at Kilauea's summit prompted scientists to raise the alert level for the Hawaiian volcano on Wednesday. But any eruption is unlikely to threaten homes. The Hawaiian Volcano Observatory said it detected 25 to 30 small earthquakes per hour since 3 a.m. at the southern part of the volcano's caldera. This spot is inside Hawaii Volcanoes National Park and far from homes. Magnitudes ranged from less than 1 to 3.4. Several quakes were large enough to be felt by observatory staff in the field. The observatory raised its alert level to “watch,” signifying that Kilauea was showing heightened or escalating unrest. This level indicates there is an increased chance the volcano will erupt, though it is unclear when. Previously, the designator for Kilauea was “advisory,” meaning the volcano was showing signs of elevated unrest above a known background level. Kilauea is one of the world's most active volcanoes. It last erupted in September, spewing lava inside the summit caldera for nearly a week. It also erupted in June. In 2018, lava burst out of cracks on Kilauea's eastern flank in its lower East Rift Zone and destroyed more than 700 homes. The observatory said there has been no unusual activity in the middle and lower sections of the East Rift Zone. Kilauea's much larger neighbor, Mauna Loa, erupted in 2022 for the first time in four decades. |
97726
From: ao, [DNS_Address]
Subject: Further Update.. 02/01
|
Things are diffidently acting up now at Kilauea. When Ry posted yesterday I was like, yeah same ol' same ol' thing, the mountain is in the long reinflation mode.. ie since the 2018 eruption in which the summit of the volcano was drained it's been refilling and eqs and inflation signals are par for the course.. But as of yesterday the summit started to deflate, and now is seriously in the red.. ie magma is moving away from, and not accumulating in the summit region. So far there is no eruption, but what is happening is magma appears to be moving towards and down the Southwest Rift Zone. This is the odder side of the volcano in that the rift is buttressed on either side by other land masses (other volcanoes) and as such is less often the way magma moves.. it's pinched.. but when the summit deflated in 2018 it created void spaces that are now free to be refilled. To appreciate this the summit tilt meter, at the time of this writing, shows about 47 microradians of tilt loss.. (my rule of thumb measurement developed over 35 years of observing this tilt meter and comparing it to eruptions is 1 microradian equals 1 million cubic meters of magma), and eqs, that are part of the swarm that has been ongoing over the last so many days, have migrated down the Southwest Rift as well.. Here's the summit tilt..  The seismicity, plotted epicenters, can be viewed here.. https://www.usgs.gov/volcanoes/kilauea Where if you become familiar with the tools available on that page will lead you to individual station's read out of the drum traces... but the trace of the closes station (DESD) to the latest events is here..  As to HVO's statements regarding these changes.. here is their update as of today.. Thursday, February 1, 2024, 9:53 AM HST From.. https://www.usgs.gov/volcanoes/kilauea/volcano-updates Activity Summary: Kilauea volcano is not erupting. The increase in seismicity and deformation that began early January 31 in the summit region has shifted from the summit to the southwest. Since last night, earthquake activity has concentrated along the Koa‘e fault system southwest of the summit. Kilauea’s summit remains pressurized; in recent months unrest has escalated quickly, and an eruption could occur in the future with little warning. Summit Observations: As of this morning, seismicity in the south caldera region has quieted, and activity is concentrated 5-7 miles (8-11 km) southwest of the caldera, in the vicinity of Pu‘ukoa‘e. Depths have remained consistent, 1–4 km (less than a mile–2.5 mi) below the surface, and the rates have persisted at 25-30 locatable earthquakes per hour. There have been over 70 locatable earthquakes in this region in the past 3 hours, with magnitudes ranging from a maximum of 3 to less than 1. Some events are large enough to be felt by neighboring communities, though none have been large enough to cause damage. Kilauea's summit region remains at a high level of inflation. Nearly 40 microradians of change have been recorded since 4:00 a.m. HST on January 31 at tiltmeters near Sand Hill and Uēkahuna bluff. Both of these tiltmeters showed highly variable directions and rates of tilt on January 31, typical of shallow crack growth that can precede either an eruption or shallow intrusion. Since early this morning, these tiltmeters have shown more consistent directions and rates, suggestive of ground inflation to the southwest (in the direction of where earthquakes are occurring). Step-wise offsets in the tilt signal are likely due to the instrument being shaken by nearby earthquakes or rockfalls. Sulfur dioxide (SO2) gas emission rates remain low. Field measurements indicated an SO2 emission rate of approximately 70 tonnes per day on January 17, which was similar to measurements in October, November, and early December. Patterns of earthquakes and ground deformation since this morning indicate that pulses of magma continue to move beneath the surface of southwest of the summit along the Ko’ae fault zone. The Koa‘e fault system connects Kilauea's East and Southwest Rift Zones south of the caldera. Faults here appear as low cliffs, or “scarps.” Typically, when magma reaches this area earthquakes are concentrated at depths of 3-4 km (2-2.5 mi), but current activity is distributed more evenly from 1-4 km (less than a mile–2.5 mi) depth. Around 7:30 this morning, three magnitude 2.9 earthquakes occurred just south of Puʻukoʻae at very shallow depths. At the time of this report, activity remains elevated; periods of increased earthquake activity and rates of ground deformation can be expected to continue in this region. Based on past historical activity, this event is much more likely to continue as an intrusion, but there is still a possibility of it ending in an eruption. A webcam view of the area where, if this event continues, an eruption might occur is here..  Which is from here.. https://www.usgs.gov/observatories/hvo/mitdcam-kilaueas-upper-southwest-rift-zone-looking-north Note: The above plots, and webcam shot are the latest, and will continue to show changes, so will outlive this event. As such they are good for viewing the changes on them over time... in other words look back later to see if things have changed.. |
97729
From: ao, [DNS_Address]
Subject: 02/01 PM Update..
URL: USGS Volcano Notice Thursday, February 1, 2024, 7:14 PM HST
|
From link above.. KILAUEA (VNUM #332010) 19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: WATCH Current Aviation Color Code: ORANGE Kilauea is not erupting. The ongoing seismic swarm continues with most earthquakes occurring beneath the Koaʻe fault zone 5-8 miles (8-12 km) southwest of Kilauea caldera. There have been roughly 15-20 earthquakes per hour in this region for most of the day. There continue to be a few scattered earthquakes within Kilauea caldera, but no significant clusters of activity. Tiltmeters at Sand Hill and Uekahuna bluff continue to show ground motion at consistent directions and rates, suggesting that the summit region is deflating as magma moves from this region to the southwest. A significant amount of lava has been intruded south and southwest of Kilauea caldera since Saturday, January 27th, 2024. Models suggest an accumulation of as much as 40 million cubic yards (30 million cubic meters) in the region to the southwest of the caldera during this event. As long as the intrusion continues, there is a chance that an eruption could occur within or southwest of the caldera with little advanced warning. Upgrades to the network may continue to cause intermittent outages that are affecting public access to monitoring data. HVO maintains internal access to volcano monitoring data and will continue to report on volcanic activity. We apologize for any inconvenience during this dynamic time. Kilauea volcano alert level and aviation color code remain at WATCH/ORANGE as the situation remains dynamic. HVO will continue to issue daily Kilauea updates; additional notices will be issued as activity warrants. |
Responses:
[97746]
97746
From: ao, [DNS_Address]
Subject: Re: 02/03 Update..
|
At the time of this writing it appears the intrusive event into Kilauea’s Southwest Rift Zone is coming to an end. As I noted in my first post there was a substantial amount of magma that was tracked, via the different sensors recording seismic and ground deformation changes, moving into the volcano’s Southwest Rift, and for awhile it was anyone’s guess as to whether or not it would result in an eruption. But now, since all signals have diminished, and especially since the tilt meters are showing no change, it’s a fairly good bet the event is over. But, and to me this is so cool, it turns out in the course of events there was a 24 hour window captured by the COSMO-SkyMed constellation of radar satellites, and the weather here was cloud free at the moment both images were acquired (that’s not as easy as it sounds) so we got the interferogram below. The one thing I’ll note is to point out that the color rings are directional, and this is important because in this image there is both land rising in some areas and falling in others. To appreciate this first look in the upper right of the image where the summit caldera is seen, and in it, to the right of the deepest crater is the center of the deflation, and there you’ll note the colors are in a descending order. Look at the ‘range change’ bar in the bottom right of the image to understand this. Then, look at the inflation centers in the left side of the picture, where it is labeled ‘Dike Opening’, and note the order of the colors are reversed.. showing the land rising.  Image Caption: This image shows ground deformation during the recent intrusive activity at Kilauea volcano. Note that this interferogram is isolated to a one-day timeframe from 6 p.m. HST on January 31 through 6 p.m. HST on February 1, 2024. It therefore highlights the volcanic signals, with reduced interference from sources of data noise. Colored fringes denote areas of ground deformation, with more fringes indicating more deformation. Each color cycle represents 1.5 cm (0.6 in) of ground motion toward or away from the satellite (the direction of motion depends on the sense of color change). The complex patterns indicate overall deflation of the summit area as magma moved underground to the southwest, where the patterns show uplift (up to about 50 centimeters, or 20 inches) and spreading (along with subsidence) due to intrusion of a dike (a vertical sheet of magma). Data are from the COSMO-SkyMed constellation of radar satellites, provided by the Italian Space Agency (Agenzia Spaziale Italiana) through the Hawaii Supersite. |
Responses:
None
97727
From: Redhart, [DNS_Address]
Subject: Re: Further Update.. 02/01
| thank you for this detailed report! |
Responses:
None
[ Earthwatchers ] [ Main Menu ]