HAWAII, US
The Hawaiian Volcano Observatory (HVO) raised the alert code to yellow (advisory) and the aviation code for Mauna Loa today to Yellow due to increased rates of inflation and seismicity under the summit and Soutwhest Rift zone. Deformation data since the end of the Kilauea eruption shows a steady increase in inflation.
HVO reports:
"For the past several months, earthquake and ground deformation rates at Mauna Loa Volcano have exceeded long term background levels. An eruption is not imminent and current rates are not cause for alarm. However, they do indicate changes in the shallow magma storage system at Mauna Loa.
Following a significant earthquake swarm in October 2018, HVO seismic stations have recorded an average of at least 50 shallow, small-magnitude earthquakes per week beneath Mauna Loa's summit, upper Southwest Rift Zone, and upper west flank. This compares to a rate of fewer than 20 per week in the first half of 2018. Shallow earthquakes are occurring in locations similar to those that preceded Mauna Loa's most recent eruptions in 1975 and 1984.
During this same time period, GPS instrumentation and satellite radar have measured ground deformation consistent with renewed recharge of the volcano's shallow magma storage system. The current rate and pattern of ground deformation is similar to that measured during inflation of Mauna Loa in 2005 and again from 2014 - 2018.
Together, these observations indicate the volcano is no longer at a background level of activity. Accordingly, HVO is elevating the Mauna Loa alert level to ADVISORY and the aviation color code to YELLOW.
Alert levels and aviation color codes are explained here: https://volcanoes.usgs.gov/vhp/about_alerts.html
This increase in alert level does not mean that an eruption is imminent nor that progression to an eruption is certain. A similar increase in activity occurred between 2014 and 2018 and no eruption occurred."
Mauna Loa, towering over Kilauea, is one of the most active volcanoes on the Big Island of Hawaii, and last erupted in 1984 in conjunction with resumed activity from Kilauea, however it has been dormant (but restless) since then.
An eruption from Mauna Loa could put structures at risk, due to it being one the of the largest shield volcanoes in the world, coupled with fast moving basaltic lavas.
HVO continues:
"Prognosis
As has happened before, it is possible that current low-level unrest will continue and vary in intensity for many months, or even years without an eruption. It is also possible that the current unrest is an early precursor to an eventual eruption. At this time, we cannot determine which of these possibilities is more likely.
HVO expects that days or weeks prior to an eruption, monitoring instruments will detect signs of an increased potential for eruption. These signs could include further increases in rates of earthquakes and ground deformation, increases in the sizes of earthquakes, an increase in surface temperatures, or an increase in visible steam plumes or sulfur dioxide emissions.
However, it is also possible that the timeframe to eruption could be shorter - hours to days. All communities on the flanks of the volcano should be prepared.
HVO continues to monitor the volcano closely and will report any significant changes. HVO is in close touch with Hawaii County Civil Defense and other agencies responsible for public safety.
Stay informed about Mauna Loa by following volcano updates and tracking current monitoring data on the HVO web page (http://hvo.wr.usgs.gov/activity/maunaloastatus.php) or by signing up to receive updates by email at this site: http://volcanoes.usgs.gov/vns/
Hawaii County Civil Defense Agency is in constant communications with HVO. If anything develops that may affect your safety, you will be informed.
Please sign up for Civil Defense notifications by visiting Hawaii County Civil Defense Agency webpage at http://www.hawaiicounty.gov/civil-defense/."
Due to this upgrade in status to Yellow, HVO will now be issuing weekly instead of monthly updates on the volcano.
It had been rumored for some time that HVO would be looking more closely at Mauna Loa after the end of eruptive activity from Kilauea, and the increased activity has been going steady since the end of that eruption. The steady rate of inflation coupled with many small quakes, and some over 3.0 in magnitude over the past year is the cause for this concern.
The eruption in 1984 crossed several roads, and threatened the town of Hilo. Development on the island since that eruption will increase the likelihood that Mauna Loa will be a threat to property. However as with most eruptions on Hawaii, it is rare that lives are threatened, except of course for the last eruptive episode on Kilauea, which resulted in a fissure system opening under a neighborhood. While some injuries did occur, no lives were lost.
The current activity seems to be centered however on the opposite side of the volcano from the 1984 eruption, which occurred on the NE rift zone and summit caldera. The current focus of seismicity seems centered on the summit caldera, and the Southwest Rift zone. This could threaten the mountainside neighborhood of Ocean View, which resides on old flows from the SWRZ, the town of Pahala (surrounded by farmland), and Naalaehu. The most likely scenario should a SWRZ eruption occur would be encroachment of lava to Ocean View, however it is far too soon to speculate.
Residents should pay close attention to HVO alerts and updates, and have a preparedness plan should Mauna Loa erupt with short warning. As was the case with the Kilauea eruption, you'd likely have weeks, days, or hours of clear signs before an eruption will be declared imminent, as this is one of the best monitored volcanoes in the world.
The Hawaiian Volcano Observatory (HVO) raised the alert code to yellow (advisory) and the aviation code for Mauna Loa today to Yellow due to increased rates of inflation and seismicity under the summit and Soutwhest Rift zone. Deformation data since the end of the Kilauea eruption shows a steady increase in inflation.
Screengrab from HVO's Mauna Loa monitoring page.
HVO reports:
"For the past several months, earthquake and ground deformation rates at Mauna Loa Volcano have exceeded long term background levels. An eruption is not imminent and current rates are not cause for alarm. However, they do indicate changes in the shallow magma storage system at Mauna Loa.
Following a significant earthquake swarm in October 2018, HVO seismic stations have recorded an average of at least 50 shallow, small-magnitude earthquakes per week beneath Mauna Loa's summit, upper Southwest Rift Zone, and upper west flank. This compares to a rate of fewer than 20 per week in the first half of 2018. Shallow earthquakes are occurring in locations similar to those that preceded Mauna Loa's most recent eruptions in 1975 and 1984.
During this same time period, GPS instrumentation and satellite radar have measured ground deformation consistent with renewed recharge of the volcano's shallow magma storage system. The current rate and pattern of ground deformation is similar to that measured during inflation of Mauna Loa in 2005 and again from 2014 - 2018.
Together, these observations indicate the volcano is no longer at a background level of activity. Accordingly, HVO is elevating the Mauna Loa alert level to ADVISORY and the aviation color code to YELLOW.
Alert levels and aviation color codes are explained here: https://volcanoes.usgs.gov/vhp/about_alerts.html
This increase in alert level does not mean that an eruption is imminent nor that progression to an eruption is certain. A similar increase in activity occurred between 2014 and 2018 and no eruption occurred."
Mauna Loa, towering over Kilauea, is one of the most active volcanoes on the Big Island of Hawaii, and last erupted in 1984 in conjunction with resumed activity from Kilauea, however it has been dormant (but restless) since then.
An eruption from Mauna Loa could put structures at risk, due to it being one the of the largest shield volcanoes in the world, coupled with fast moving basaltic lavas.
Footage of previous Mauna Loa Eruption
HVO continues:
"Prognosis
As has happened before, it is possible that current low-level unrest will continue and vary in intensity for many months, or even years without an eruption. It is also possible that the current unrest is an early precursor to an eventual eruption. At this time, we cannot determine which of these possibilities is more likely.
HVO expects that days or weeks prior to an eruption, monitoring instruments will detect signs of an increased potential for eruption. These signs could include further increases in rates of earthquakes and ground deformation, increases in the sizes of earthquakes, an increase in surface temperatures, or an increase in visible steam plumes or sulfur dioxide emissions.
However, it is also possible that the timeframe to eruption could be shorter - hours to days. All communities on the flanks of the volcano should be prepared.
HVO continues to monitor the volcano closely and will report any significant changes. HVO is in close touch with Hawaii County Civil Defense and other agencies responsible for public safety.
Stay informed about Mauna Loa by following volcano updates and tracking current monitoring data on the HVO web page (http://hvo.wr.usgs.gov/activity/maunaloastatus.php) or by signing up to receive updates by email at this site: http://volcanoes.usgs.gov/vns/
Hawaii County Civil Defense Agency is in constant communications with HVO. If anything develops that may affect your safety, you will be informed.
Please sign up for Civil Defense notifications by visiting Hawaii County Civil Defense Agency webpage at http://www.hawaiicounty.gov/civil-defense/."
Due to this upgrade in status to Yellow, HVO will now be issuing weekly instead of monthly updates on the volcano.
It had been rumored for some time that HVO would be looking more closely at Mauna Loa after the end of eruptive activity from Kilauea, and the increased activity has been going steady since the end of that eruption. The steady rate of inflation coupled with many small quakes, and some over 3.0 in magnitude over the past year is the cause for this concern.
The eruption in 1984 crossed several roads, and threatened the town of Hilo. Development on the island since that eruption will increase the likelihood that Mauna Loa will be a threat to property. However as with most eruptions on Hawaii, it is rare that lives are threatened, except of course for the last eruptive episode on Kilauea, which resulted in a fissure system opening under a neighborhood. While some injuries did occur, no lives were lost.
The current activity seems to be centered however on the opposite side of the volcano from the 1984 eruption, which occurred on the NE rift zone and summit caldera. The current focus of seismicity seems centered on the summit caldera, and the Southwest Rift zone. This could threaten the mountainside neighborhood of Ocean View, which resides on old flows from the SWRZ, the town of Pahala (surrounded by farmland), and Naalaehu. The most likely scenario should a SWRZ eruption occur would be encroachment of lava to Ocean View, however it is far too soon to speculate.
Residents should pay close attention to HVO alerts and updates, and have a preparedness plan should Mauna Loa erupt with short warning. As was the case with the Kilauea eruption, you'd likely have weeks, days, or hours of clear signs before an eruption will be declared imminent, as this is one of the best monitored volcanoes in the world.
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