The Volcano Guards is a weekly article and activity update written by scientists and associates of the Hawaiian Volcano Observatory Geological Survey.
The USGS Hawaiian Volcano Observatory (HVO) has several seismometers used throughout Kīlauea Volcano to monitor volcanic processes and active fault movements. When magma does not move internally or erupt from Kīlauea, the group microseisms appear on seismometers as a repetitive and unchanged signal.
The microseismic signals show large changes during periods when Kīlauea enters or breaks down due to magma moving below its surface. Similar changes occur when the volcano is actively erupting, as now. Scientists measure differences in these observational microseisms during periods of volcanic activity compared to quiet periods, in an attempt to determine when, where, and how far magma migrates and stored within Kīlauea.
HVO scientists recently applied this technique to better understand the events leading up to the 2018 East Rift Zone eruption and peak collapse. Microseism data combined with more traditional seismic and deformation patterns record a pressure increase within the shallow area of the magma storage reservoir at the top of Kīlauea. Both the summit and the Eastern Rift Zone began to expand rapidly, suggesting that magma was moving into these regions.
Changes in microseisms also showed that an earthquake of magnitude 5.3 years earlier had significantly weakened the volcanic eruption under Pu’u ‘Ō’ō. HVO scientists assumed that the combination of increased pressure at the top of Kīlauea and the weakening of the shallow crust under Pu’u ‘Ō’ō created conditions conducive to magma moving down and exploding there. in 2018.
HVO scientists recently released an additional eight temporary seismometers around the Halemaʻuma crater, at the top of Kīlauea, to monitor magma movements under the new lava lake. These temporary seismometers, together with a permanent HVO seismic network, allow greater spatial sampling of the oceanic microseisms traveling through the Kīlauea magma reservoir. This in turn means deeper sampling of where physical changes occur beneath the crater.
The confinement of the continuous explosion inside the Halema`uma crater at the top of Kīlauea is particularly suitable for the study of the physical apparatus associated with this explosion. By analyzing these data, scientists at HVO hope to answer several questions: 1) where is the source of magma and pathways for this explosion ?; 2) can this approach help us to understand small increases and decreases in volcanic activity that have been seen at times during this eruption ?; 3) can this device give hints when the explosion will end ?; and 4) how can we apply what we have learned in this study to help better understand and predict volcanic activity related to future eruptions at Kīlauea?
Volcanic activity updates
The Kīlauea volcano is erupting. It has its USGS volcano Alert level at WATCH (https://www.usgs.gov/natural-hazards/volcano-hazards/about-alert-levels). Kīlauea updates are issued daily.
Lava activity is limited to Halemaʻumaʻu with lava erupting from wine on the northwest side of the crater. A field laser measurement this morning, March 18, shows that the lava in the western (active) part of the lake is 221 m (725 ft) deep, with the eastern part of the lava lake on the solidification at the surface. The roof tiltmeters did not record inflation or deflation tilts over the past day. Sulfur dioxide emission levels measured on March 17 were 650 t / d. Seismicity remains stable, with high vibration. For the latest information on the explosion, see https://www.usgs.gov/volcanoes/kilauea/current-eruption.
Mauna Loa is not exploding and she lives at the Volcano Alert Stage Council. This level of warning does not imply that an explosion is imminent or that progress to an explosion from the current level of disturbance is certain. Mauna Loa updates are provided weekly.
Last week, about 163 minor earthquakes were recorded under the high altitudes of Mauna Loa; most of these occurred at depths of less than 6 kilometers (about 4 miles). Global Positioning System (GPS) measurements show slow, continuous inflation consistent with magma supply to the shallow storage system of the volcano. A slight rise in the rate of inflation at the peak, which began in January, continues. Gas density and fumarole temperature both at the summit and at Cone Sulfur on the Southwest Rift Zone are stable. Webcams do not show any changes in the landscape. For more information on routine survey of the Mauna Loa volcano, see: https://www.usgs.gov/volcanoes/mauna-loa/monitoring.
There were 7 incidents with 3 or more emotion reports in the Hawaiian Islands over the past week: M3.3 earthquake 0 km (0 mi) NNW of a Volcano at a depth of 26 km (16 mi) on March 17 at 3:33 am HST, earthquake M2.7 26 km (16 mi) E of Honaunau-Napoopoo depth at -1 km (0 mi) on March 17 at 3:27 am HST, earthquake M3. 2 3 km (1 mi) S of Pāhala at a depth of 32 km (20 mi) on March 17 at 12:25 m HST, earthquake M1.3 25 km (15 mi) N of Pāhala at a depth of 7 km (4 mi) on March 15 at 1:47 am HST, M4.1 earthquake 12 km (7 mi) SSE of a volcano at a depth of 7 km (4 mi) on March 14 at 8:59 pm HST, earthquake M3.3 53 km (32 mi) ENE of Honomu at 5 km (3 mi) depth on March 12 at 5:38 pm HST, and M3.4 earthquake 54 km (33 mi) ENE of Honomu at a depth of 2 km (1 mi) at 12 March at 5:31 pm HST.
HVO is closely monitoring both Kīlauea and Mauna Loa’s continuous explosion for any signs of increased activity.
Please visit the HVO website for past Volcano Guards articles, Kīlauea and Mauna Loa updates, volcano photos, maps, recent earthquake information, and more. Email questions to [email protected].
Volcano Watch is a weekly article and activity update written by scientists and relatives of the US Geological Survey Hawaiian Volcano Observatory.