What causes an eruption to pause? A pause is caused by an interruption in the supply of magma to the eruption site or vent. Now, how do we know the eruption has paused? Well, that's a deceptively simple question with a surprisingly complex answer in this situation.
Molten lava is glowing red and generally easy to spot erupting from the vent, especially at night. And, likewise, generally easy to tell when it's stopped. However, in the case of the lava lake, the vent supplying the lava eventually crusted over and lava was no longer visible.
The best way to tell if lava is still filling the crater (without being able to see the lava) is to see if the level of lava in the lake is continuing to rise. The crater forms a natural measuring cup, except that it's a very strange shape and it has no markings to use to measure volume. We measure the distance to the surface of the lava lake using laser rangefinder instruments and then apply some algebra, trigonometry, and a computer to find the depth, volume, and lava supply rate of the lava lake.
The amount of sulfur dioxide gas (SO2) being released from the vent is directly related to the amount of lava being erupted. Both erupted lava volume, approximately 8 million cubic meters or 10 million cubic yards per day, and SO2 gas release, 40,000 tonnes per day, were extremely high at the beginning of the eruption. These exponentially decreased over the course of the eruption to about 70,000 cubic meters or 90,000 cubic yards of lava per day and less than 1000 tonnes of SO2 per day by early- to mid-April.
Halema‘uma‘u the morning after the eruption began on Dec. 21. The eruption is now on pause. USGS photo. |
The eruption rates and SO2 gas emissions declined precipitously after April 16th, coincident with the level of lava in the lake reaching the level of the vent. This relationship suggests that the colder, degassed lava within the lake essentially drowned the vent.
This period also saw a decrease in seismic tremor related to magma movement and degassing within the dike feeding the vent. In addition, a weak pattern of inflation associated with increased earthquakes beneath Kīlauea caldera suggest that magma has shifted to accumulating at depth instead of rising to the surface.
Finally, the top of the lava lake crusted over as the lava supply dwindled and stopped, with the last surface activity seen on May 23rd. So, without being able to directly see if new lava was entering the lake, USGS Hawaiian Volcano Observatory scientists used lava lake depth measurements to infer that the lava supply stopped and that the eruption "paused."
Many eruptions undergo brief pauses then resume activity within the same vents. There were numerous pauses followed by resumption of activity during the Puʻuʻōʻō eruption and many have also been recorded in the past including during the Maunaulu, Kīlauea Iki, and 1955 lower East Rift Zone eruptions.
So, how do we know if the 2020–21 Halemaʻumaʻu eruption is paused or pau? Statistically, most eruptions that resume, do so within 3 months after pausing. For now, we can only watch and wait to see if activity returns to this same vent system ending the pause. Or alternatively, if the eruption is truly pau, we may be entering a period of quiescence prior to Kīlauea's next eruption.
Using digital elevation models (DEMs), created from photos taken during helicopter overflights of Kīlauea's summit, HVO scientists tracked the rise of the lava lake (bottom panel). The top two panelsshow a pre-eruption DEM of Halema'uma'u crater from 2019 (top left) and a DEM of the crater fromMay 13. (top right). The red line in the top panels shows the elevation profile line used for the bottom panel, which measures one mile in length. The profile shows the "cone-like" shape of the crater that led to rapid filling early in the eruption when effusion rates were high. The level of the lake rose much more slowly from January to May as the effusion rate declined and the surface area increased. The final depth of the lava lake is 229 m (751 ft) and the final volume is 41.2 million cubic meters (54 million cubic yards). USGS graphic and data processing by B. Carr |
HPD reports that on island, DUI arrests are up 47.1 percent compared to the same time last year. Every day, 28 people in the United States die in an alcohol-related vehicle crash—that’s one person every 53 minutes. Drunk driving fatalities have fallen by a third in the last three decades; however, the chance of being in an alcohol-impaired crash is still one in three over the course of a lifetime. These deaths and damages contribute to a cost of $52 billion per year.
An HPD statement urges: "Please do your part to keep our roads safe. Always remember to have a designated sober and licensed driver before you start drinking. If you don’t find one, don’t take a chance—take a taxi or use a ride share program like Uber or Lyft."
This is an outdoor event. |
"With summer right around the corner, many residents look forward to harvesting local fruits across Hawaiian Electric’s five-island service territory. But the company wants residents to stay safe and avoid
Hawaiian Electric warns against trimming trees and picking fruit near overhead power lines. Photo from Hawaiian Electric |
Hawaiian Electric offers these tips: Always look up and around for power lines before starting any harvesting or trimming activity. If any part of the tree is touching overhead power lines, the tree can become energized and you should not touch the tree. Use the 10-foot-rule: Always keep your body and any ladders, tools or other implements at least 10 feet away from overhead power lines. Don't use ladders or fruit pickers near power lines. Keep any type of ladders, fruit pickers, poles or other tools at least ten feet away from the lines.
Never trim trees that have power lines going through them or touch any tree limb that may fall into a power line. It is strongly recommended that a qualified arborist be used to trim and maintain trees, especially trees near power lines. If a person comes into contact with a power line, assume the line is energized and dangerous. Do not attempt to free the person from the power line. Steer clear and warn others to keep away. Call 911 immediately for emergency help.
When seeing any object caught in a power line, assume the line is energized and do not attempt to free it. Call Hawaiian Electric's Trouble Line at (808) 969-6666 or call 911 in an emergency.
KAʻŪ ART GALLERY CONTINUES ITS MOTHERS DAY SALE THROUGH THE END OF MAY. It is open Wednesdays and Saturdays from 9 a.m. - 3 p.m. in Nāʻālehu. It features and sells works by local artists and offers other gift items. Kaʻū Art Gallery's website has 24/7 access online and is frequently updated to show current inventory items. "We are always looking to collaborate with local artists in our community," said assistant Alexandra Kaupu. Artists with an interest in being featured at Kaʻū Art Gallery and Gift Shop, contact gallery owner and director Corrine Kaupu at kauartgallery@hawaiiantel.bi
Call 808-731-5122 or stop by the Clubhouse during business hours, 8 a.m. to 4 p.m. daily at 94-1581 Kaulua Circle. Email clubatdiscoveryharbour@gmail.com.
See The Club at Discovery Harbour Facebook page.
KUAHIWI RANCH STORE, in person. Shop weekdays, 10 a.m. to 5 p.m., Sunday, 11 am to 3 p.m. at 95-5520 Hwy 11. Locally processed grass-fed beef, live meat chickens, and feed for cattle, goats, sheep, chickens, horses, dogs, and pigs. Call 929-7333 of 938-1625, email kaohi@kuahiwiranch.com.
CHURCH SERVICES
Public Libraries are open for WiFi, pick-up, and other services. Nāʻālehu open Monday and Wednesday, 9 a.m. to 4 p.m., Friday, 11 a.m. to 4 p.m. Nāʻālehu open Tuesday, noon to 7 p.m., Thursday, 9 a.m. to 4 p.m., limited entry into library with Wiki Visits. Schedule a Library Take Out time at picktime.com/hspls. Open for library card account help and reference assistance from the front door. WiFi available to anyone with a library card, from each library parking lot. See librarieshawaii.org.
Free Book Exchanges, at laundromats in Ocean View and Nāʻālehu, provided by Friends of the Kaʻū Libraries. Open to all. Keep the books, pass them on to other readers, or return them. Selection of books replenished weekly at both sites.
Read Report on Public Input about Disaster Recovery from damage during the 2018 Kīlauea eruption.
Food Assistance: Apply for The Volcano School of Arts & Sciences COVID-19 Family Relief Funds. Funded by Volcano Community Association, and members of the VSAS Friends and Governing Boards, who have donated, the fund supplies KTA or Dimple Cheek Gift Cards, or gift cards to other locally owned business, to VSAS families in need. Contact Kim Miller at 985-8537, kmiller@volcanoschool.net. Contributions to the fund can be sent in by check to: VSAS, PO Box 845, Volcano, HI 96785 – write Relief Fund in the memo. See volcanoschool.net.
Apply for Utility Assistance to pay for electricity, non-government water, or gas. Applicants must be a Hawaiʻi Island resident, at least 18 years old, lost income or work hours due to COVID-19, and not previously received assistance from other COVID-19 federal or state-funded programs. Funded by CARES Act and distributed by Hawaiʻi County Economic Opportunity Council, required documents for application are government-issued identification, income verification documents for all household members, utility statement with address of services, lease/rental agreement or mortgage document, and proof of hardship. Hardship may include, but not limited to, pay stubs documenting pre-COVID-19 income, unemployment approval letter, or layoff letter. Apply at HCEOC.net or call 808-961-2681.
Apply for Expanded Hawaiʻi County Rent and Mortgage Assistance Program. Contact RMAP partners: Hawaiian Community Assets/Hawaiʻi Community Lending, HawaiianCommunity.net, 808-934-0801; HOPE Services Hawaiʻi, hopeserviceshawaii.org/rmap, 808-935- 3050; Hawai‘i First Federal Credit Union, hawaiifirstfcu.com/pathways, 808-933- 6600; Neighborhood Place of Puna, neighborhoodplaceofpuna.org/coronavirus-rent-mortgage-relief, 808-965-5550; Hawai‘i Island Home for Recovery, hihrecovery.org/RMAP, 808-640-4443 or 808- 934-7852; Habitat for Humanity Hawai‘i Island, habitathawaiiisland.org/rmap.html, 808-450-2118.
Apply for Holomua Hawaiʻi Relief Grants for small businesses and nonprofits, up to $10,000, support core operations, safe on-going and reopening costs, personal protective equipment, and training and technical assistance. The business or nonprofit must employ 50 people or fewer. See rb.gy/v2x2vy.