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Waimea Town Meeting to Explore ‘Restless’ Mauna Loa

April 3, 2018, 8:06 AM HST
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Glow from a Mauna Loa lava flow lit up the night sky above Hilo on April 4, 1984. In this photo, captured from near the Hilo airport, the flow front appears closer to the city than it actually was. Should a similar eruption occur in the future, the U.S. Geological Survey’s lava flow inundation maps could help alleviate concern for residents outside the identified inundation zone for a given flow. PC: David Little.

The unique aspects of “restless” Mauna Loa will be the topic of discussion at 5:15 p.m. on Thursday, April 5, 2018, at Waimea Community Association’s meeting at the Waimea Elementary School cafeteria.

Although Waimea is not located on the slopes of Mauna Loa—the largest volcano on Earth, comprising more than half of the surface area of Hawai’i Island—the unique geology and history of this nearby volcano will be in the spotlight.

While the U.S. Geological Survey Hawaiian Volcano Observatory (USGS-HVO), which is responsible for monitoring Hawaiian volcanoes and earthquakes, does not expect Mauna Loa to erupt in the near future, it is, HVO scientists say, time for Hawaiʻi residents to learn more about the massive volcano in their backyard and become aware of its potential hazards.

Tina Neal, scientist-in-charge of the USGS-HVO, will describe the eruptive history and current status of Mauna Loa. Informative USGS fact sheets and other informative handouts will also be available.

According to a recent HVO “Volcano Watch” article, Mauna Loa has erupted 33 times since 1843, most recently in 1984. All 33 eruptions began at the summit of Mauna Loa—with about half of them starting and staying in the volcano’s summit area. Of the remainder, about 24% of the eruptions started at the summit and then migrated down Mauna Loa’s Northeast Rift Zone, sending lava flows
toward Hilo. Another 21% started at the summit and then migrated to lower elevations along the volcano’s Southwest Rift Zone, sending lava flows toward Ka‘ū and South Kona.


Equally significant is the fact that Mauna Loa eruptions produce large, fast-moving lava flows that can travel from the vent to the sea in a matter of hours. For example, during the 1950 Mauna Loa eruption, lava flows that erupted from vents high on the Southwest Rift Zone reached the ocean in South Kona in only three hours.  Along the way, the flows severed roads and utilities, disrupted communications and travel, repaved the flanks of the volcano with large ‘a‘ā flows, and emitted copious amounts of volcanic gas that greatly diminished air quality downwind of the vent.


In 2015, the Volcano Alert Level for Mauna Loa was elevated from “Normal” to “Advisory” due to increased seismicity and deformation. While Mauna Loa’s earthquake and swelling rates have slowed in recent months, they are still above the pre-2013 rates and could increase again, so for now, the volcano’s alert level remains at “Advisory.”

In addition to the unique geologic characteristics of Mauna Loa is the fact that the population of Hawai‘i Island has essentially doubled since Mauna Loa’s most recent eruption in 1984—almost 34 years ago. So, a generation of kama‘āina (Hawai‘i-born residents), as well as malihini (island newcomers) have not experienced a Mauna Loa eruption, which can produce large, fast-moving ‘a‘a flows.

For example, during the 1984 eruption, Mauna Loa erupted in about 20 minutes the same volume of lava that Kīlauea erupts, on average, in one day. A 1950 Mauna Loa lava flow traveled 13 miles from its Southwest Ridge Zone to the South Kona coast in just over three hours. In contrast, the 2014 Kīlauea lava flow that threatened Pāhoa took four months to travel a similar distance.


So, experiencing Kīlauea pahoehoe flows does not necessarily prepare the public for Mauna Loa ‘a’a flows.

“Given the volcano’s past eruptions and recent unrest, it’s wise to talk about Mauna Loa now—well before an eruption is about to happen,” said HVO. “Thus, we are informing residents about the eruptive history, hazards, and current status of earth’s largest active volcano. Our challenge is to increase awareness of Mauna Loa and how to prepare for a future eruption without creating unnecessary anxiety.”

Neal began her USGS career in 1983 at USGS-HVO, studying the Pu‘u ‘Ō‘ō eruption and preparing updated geologic maps of Kīlauea’s summit and Southwest Rift Zone. In 1990, she joined the Alaska Volcano Observatory (AVO), where she conducted geologic mapping and studied eruptions and unrest at more than a dozen Aleutian volcanoes. From 1998 to 2000, she served as the first geoscience advisor to the Office of U.S. Foreign Disaster Assistance. From 2005 to 2015, Neal led USGS-AVO’s cooperative work with volcanologists at observatories in the Russian Far East. Then in March 2015, she returned to HVO as scientist-in-charge, focusing on staff development and support, monitoring of Kīlauea’s ongoing eruptions, and preparing for the next eruption of Mauna Loa.

Joining Neil for the presentation will be geologist-educator Janet Babb, who came to Hawai‘i in 1990 from New Mexico to spend a summer volunteering at HVO and ended up moving to the island. She continued to volunteer part-time at HVO while teaching geology at the University of Hawai‘i at Hilo, and then established private guided hikes on Kīlauea. She joined HVO as a full time geologist in 2008. Her primary duties are public information, media and educational outreach.

Also on the WCA Town Meeting agenda will be a brief update on Waimea’s Domestic Violence Action
Committee (DVAC), which started holding monthly victim support gatherings after the community held a vigil here in late 2016 in response to numerous incidents of domestic violence. DVAC involves the county prosecutor’s office, Waimea Community Policing and many volunteers and serves Waimea, Waikoloa and North Kohala. DVAC, under the leadership of CPO May Lee with the South Kohala police station, recently succeeded in helping establish issuance of temporary restraining orders (TROs) by the South Kohala family court. The group is currently working to secure grant and private donor funding to hire a domestic violence “navigator” to support victims in securing needed supports.

DVAC, which is part of Friends of the Future, will be WCA’S spotlighted nonprofit for April.

As always, there is no charge to attend WCA Town Meetings and everyone is invited. Membership in WCA is encouraged and runs $15 for individuals and $25 per family per year.

For more information, go online or or call Patti Cook at (808) 937-2833.

Waimea Elementary School is located at 67-1225 Hawai‘i Belt Road.


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