VOLCANOES NATIONAL PARK — My 37-year stint with the U.S. Geological Survey—16 years at the Cascades Volcano Observatory (CVO) and 21 at the Hawaiian Volcano Observatory (HVO) — ends this month.
I feel privileged to have spent a long career observing volcanoes, supporting my colleagues, and striving to help people understand the potential impacts of eruptions. Upon reflection, I’m struck by the extraordinary “collapse” events that bookended my career, beginning at Mount St. Helens in 1981 and ending at Kilauea Volcano in 2018.
It took only minutes for the top and north flank of Mount St. Helens volcano to collapse in a massive landslide on May 18, 1980. The fearsome eruption that followed led to the creation of CVO — modeled after HVO — for scientists to focus long-term investigations and keep a watchful eye on Cascade Range volcanoes.
My journey with volcanoes began there as a surveyor in the debris-clogged river valleys downstream of Mount St. Helens. Soon thereafter, I volunteered to serve as media liaison for CVO. Fifteen years later, I moved to Hawaii to coordinate and develop HVO’s website.
This month, my USGS career is ending on the heels of the collapse of Halemamau and adjacent caldera floor at the summit of Kilauea. The collapse occurred as an enormous outpouring of lava on the volcano’s lower East Rift Zone 25 miles away buried more than 700 homes and 13.7 square miles of land with flows as thick as 80 feet.
Halemamau was eventually deepened by more than 1,600 feet and widened by 1.1 miles equivalent to a volume loss of 1.2 billion cubic yards. As magma drained from the summit reservoir, the overlying crater floor collapsed piecemeal more than 60 times, dropping more than 6.5 feet with each event. Each of these collapses released energy equivalent to that of a magnitude-5 earthquake.
Many eruptions in the U.S. and abroad, some with dire consequences, spanned the volcano-collapse bookends of my career. Only four years into my work at CVO, the 1985 eruption of the Colombian volcano Nevado del Ruiz killed more than 25,000 people when lahars (volcanic mudflows) swept down several river valleys.
Thousands of people had, for many decades, unknowingly built their communities on lahar deposits from earlier eruptions of the volcano. This eventually created the dilemma faced by Colombian authorities when the volcano awakened a year before the deadly eruption: How long could evacuation of thousands of people be delayed to minimize economic upheaval and political costs of a too-early evacuation or false alarm?
This dilemma is universal for current emergency-management authorities and elected officials as increasing numbers of people live and work on the slopes of volcanoes or within areas known for potential volcanic hazards.
The dilemma also creates increasing challenges for scientists to improve their capabilities to monitor and interpret volcanic behavior so they can issue more accurate and timely warnings of eruptions and potential consequences. They must also effectively communicate the results of their work before, during, and after eruptions to raise awareness of volcano hazards to an increasingly interested and demanding media and public.
USGS work on volcanoes, primarily in the U.S. but also abroad, is possible because of the long-term public investment in our nation’s five volcano observatories. The ever-growing knowledge and experience of observatory personnel with different volcanoes and types of eruptions are invaluable for helping to prevent future volcano emergencies from becoming volcanic disasters.
I bid a fond farewell to my colleagues at HVO and the other four U.S. volcano observatories, as well as other volcano scientists, emergency professionals, educators, land managers, naturalists, and media with whom I’ve had the pleasure of working. And to everyone in Hawaii who has supported and challenged HVO and participated in dozens of community meetings during the past few years, mahalo nui loa (many thanks) for your sincerest aloha!
Volcano Activity Updates
At Kiauea’s lower East Rift Zone (LERZ) and summit, seismicity and ground deformation remain low. Active lava has not been seen within the fissure 8 cone since September 5, and the high rates of seismicity and deflationary deformation at the summit stopped abruptly on August 4. Hazardous conditions still exist at both the LERZ and summit. Residents in the lower Puna District and Kilauea summit areas on the Island of Hawaii should stay informed and heed Hawai’i County Civil Defense closures, warnings, and messages.
No collapses at Puu O o have been observed during the past week.
The combined sulfur dioxide emission rates at Kilauea’s summit, Puu O o, and lower East Rift Zone is less than 300 tonnes per day—lower than at any time since late 2007.
The USGS Volcano Alert level for Mauna Loa remains at NORMAL.
HVO continues to closely monitor both Kīlauea and Mauna Loa and will report any significant changes on either volcano. Daily Kīlauea updates are posted at https://volcanoes.usgs.gov/volcanoes/kilauea/status.html. Monthly Mauna Loa updates are posted at https://volcanoes.usgs.gov/volcanoes/mauna_loa/status.html.
Three earthquakes with three or more felt reports occurred in the Hawaiian Islands this past week: a magnitude-3.1 quake 17 miles west of Pepe’ekeo at 12 miles depth on Oct. 1 at 12:05 p.m. HST; a magnitude-3.4 quake 13 miles east-northeast of Hōnaunau at 3 miles depth on Sept. 30 at 10:46 a.m. HST; and a magnitude-4.0 quake 7 miles south-southeast of Kapa’au at 14 miles depth on Sept. 28 at 12:05 a.m. HST. Small aftershocks from the May 4, 2018, magnitude-6.9 earthquake are still being generated on faults located on Kilauea’s south flank.
Please visit HVO’s website or past Volcano Watch articles, Kilauea and Mauna updates, volcano photos, maps, recent earthquake info, and more. Call 967-8862 for a Kilauea summary update. Email questions to askHVO@usgs.gov.
Volcano Watch is a weekly article and activity update written by U.S. Geological Survey Hawaiian Volcano Observatory scientists and affiliates. This week’s article was written by HVO geophysicist Ingrid Johanson.
