Pushing the volcano monitoring envelope

Like other volcano observatories, HVO devotes most of its resources to volcano monitoring, using time-tested methods that have been found to deliver data useful for understanding and forecasting volcanic behavior. But the monitoring toolkit is not static; it evolves as new technologies become available and as new monitoring strategies are introduced.

Before a new method is adopted, someone has to imagine it—and imagine that it might be superior to an existing method or provide information that is otherwise unavailable. Many volcano-monitoring tools have been adopted from other disciplines, when a volcanologist recognizes the applicability to volcanology. Two examples are interferometric synthetic aperture radar (INSAR) and Doppler radar. INSAR can detect subtle changes in the earth’s surface over broad areas. Doppler radar—used to detect and track plumes from explosive eruptions—was adopted from the meteorological community. Doppler radar images are frequently seen on television weather forecasts. Both INSAR and Doppler radar evolved from radar developed for military applications.

The idea for a new method may spring from a chance observation. For example, pioneering volcanologist Frank Perret, responding to a volcanic crisis at Vesuvius in 1906, wrote: “At the Eremo Hotel, opposite the Royal Observatory, I thought I could hear in the dead of night a low buzzing sound. On opening the window the buzzing ceased, but with my ear to the pillow it again became distinctly audible. With my teeth in contact to the iron bedstead the noise was unquestionably louder, and there was no doubt in my mind that a contact microphone would have shown the sound to be of subterranean origin, definitely premonitory of threatening danger.”

Whatever the source of the idea, it needs to be tested. The outcome of such a test is of course uncertain—otherwise the test wouldn’t be necessary. Many “good ideas” don’t pan out. Frank Perret constructed and tested his contact microphone, but it has not become part of the modern toolkit. On the other hand, seismographs, which measure lower vibrational frequencies, have become the foundation of the volcano-monitoring toolkit.

Observatories can devote only a small fraction of their resources to testing new ideas—just as a prudent stock portfolio manager will allocate only a small fraction of a portfolio to high-risk but potentially high-return stocks.

HVO currently has several speculative stocks in its portfolio. One is the use of multiple continuously recording gravimeters—instruments that accurately measure the pull of gravity. Gravity measurements can detect subtle density changes caused by magma movement beneath the instrument. Gravimeters are notoriously difficult to operate and, traditionally, each measurement has been made manually. The use of continuously recording instruments is new—and experimental.

The study of lava-tube tremor is also experimental. This study was designed to test the idea that fluid motions in flowing tube-lava would generate vibrations. It was hoped that the amplitude and/or frequency of the vibrations would track the lava flux—that is, the rate at which lava flows through the tube. If this were true, we could monitor the changes in Kīlauea’s output in real time. Data collected from seismometers placed atop lava tubes show that lava tubes do indeed produce continuous vibrations, or tremor. And it appears that the tremor amplitude tracks the lava flux over periods of at least a week. Future experiments will collect data over longer time periods.

A third experiment will deploy a number of thermal infrared web cameras. Infrared light penetrates ash and fume better than visible light, so these cameras should be able to provide continuous images of the lava lake within Halema`uma`u Crater. The visible-light cameras currently in use can only see through the fume at night. In addition to images, these new cameras also provide quantitative temperatures that can be monitored for unusual changes over time.

All of these experiments—and others not described—are promising. But they will find their way into regular use only after testing demonstrates that the information they provide is sufficiently useful to justify the cost of procurement and maintenance in a challenging environment.

Kilauea Activity Update

There were several small breakouts just west of the end of Highway 130 last weekend, and a few small breakouts on the Puhi-o-Kalaikini delta at mid-week. All were short-lived and posed no threat to the nearby Kalapana Gardens subdivision. A series of inflation–deflation cycles, ongoing at Kilauea’s summit for the past several weeks, may result in fluctuations in the size of the ocean entry plume over the coming days and could result in more small breakouts on the coastal flow field.

At Kilauea’s summit, a circulating lava pond deep in the collapse pit within the floor of Halema`uma`u Crater was visible via the Webcam throughout the past week. The lava surface rose and fell slowly to match the series of deflation–inflation cycles. This slow change in lava level was punctuated on several occasions by abrupt increases in the height of the lava surface. These periods of high lava level were short-lived, lasting up to several hours, and ended with a sudden drop of the lava surface back to its previous level. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

Three earthquakes beneath Hawai`i Island were reported felt during the past week. A magnitude-2.5 earthquake occurred at 3:31 p.m. on Thursday, August 19, 2010, H.s.t., and was located 6 km (4 miles) west of Kilauea summit at a depth of 9 km (6 miles). A magnitude-3.1 earthquake occurred at 3:01 p.m. on Monday, August 23, and was located 15 km (10 miles) west of Pahala at a depth of 8 km (5 miles). A magnitude-2.7 earthquake occurred at 3:26 p.m. on Wednesday, August 25, and was located 16 km (10 miles) west of Kilauea summit at a depth of 11 km (7 miles).

Visit the HVO Web site for detailed Kilauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call (808) 967-8862 for a Kilauea summary; email questions to askHVO@usgs.gov.

Volcano Watch is a weekly article and activity update written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.

Hawaii Wins ‘Race to the Top’ Education Grant

Governor Linda Lingle today applauded the collaborative efforts of education and community partners that resulted in Hawai‘i being named a Race to the Top grant winner. The U.S. Department of Education made the announcement this morning that Hawai‘i is among 10 states and the District of Columbia in the competition’s second round of grant awards.

Hawai‘i will receive $75 million to implement comprehensive initiatives to reform the state’s public education system to improve student achievement.

“We are extremely pleased and proud that the U.S. Department of Education has approved Hawai‘i’s Race to the Top application,” said Governor Lingle. “With the Race to the Top funding and the support of the U.S. Department of Education, Hawai‘i has a tremendous opportunity to make the systemic changes needed to raise performance in the classroom so students are prepared for college and their careers,” said Governor Lingle.

“Getting to this point would not have been possible without the dedication and hard work of the Hawai‘i Department of Education – under the leadership of interim Superintendent Kathryn Matayoshi – the Board of Education, the community and my Administration,” the Governor said.

“Securing this grant is just a stepping stone. We will now begin the hard work of implementing our education reform plan, which includes a common core curriculum tied to a new on-line state test while tracking student progress and rewarding teachers by linking 50 percent of their evaluation to student achievement. I am especially excited about our pledge to have 100 percent of high school graduates ready for a career and college without the need for post secondary remediation programs,” the Governor added.

Comments Sought on Pearl Harbor Wildlife Refuge

The U.S. Fish and Wildlife Service is inviting the public to comment on the draft comprehensive conservation plan and environmental assessment for Pearl Harbor National Wildlife Refuge on O‘ahu. When final, the plan will guide management of the refuge for the next 15 years. More >

Mystery Unraveled: How Asbestos Causes Cancer

More than 20 million people in the U.S., and many more worldwide, who have been exposed to asbestos are at risk of developing mesothelioma, a malignant cancer of the membranes that cover the lungs and abdomen that is resistant to current therapies. Moreover, asbestos exposure increases the risk of lung cancer among smokers. For the past 40 years researchers have tried to understand why asbestos causes cancer. More >

Dealing with Hazards is a Risky Business

Volcanic hazards come in many forms. The most common hazards for Hawai‘i include earthquakes, lava flows, and wide-ranging vog. What is the definition of hazard?

Merriam-Webster defines “hazard” as a source of danger. Other definitions from dictionary.com include 1) an unavoidable danger or risk, 2) something causing unavoidable danger, peril, risk, or difficulty. In the last two definitions, the term “risk” is introduced. What is “risk”?

“Risk” is defined by dictionary.com as “exposure to the chance of injury or loss; a hazard or dangerous chance.” In volcanology, risk has been defined as the impact (damage) that an event would have on humans within the area affected. This extends to person(s), property, or anything of economic value.

Risk can be defined as the mathematical product of hazard, vulnerability, value, and likelihood (assuming that these concepts can be expressed in numbers).

Everyone on the Island of Hawai`i should be aware of the fact that there are at least three active volcanoes and that lava flows present a significant hazard. The most persistent hazard is vog. Yet, the most damaging hazard is a large earthquake, such as the 2006 Kiholo Bay earthquake that impacted communities as far away as O`ahu.

Simply defined, “vulnerability” is the percentage of value likely to be lost if a hazardous event occurred. If lava contacts your wooden house, it will burn; the house is 100 percent vulnerable. Many houses survived the 2006 Kiholo Bay earthquake with minor damage thanks to improved building codes; therefore, the vulnerability was a small fraction of the cost of a new home.

“Value” is defined explicitly as the dollar amount of life and (or) property that is lost by a hazardous event. Some things are easily tabulated because we see and use them in everyday life—homes lost, roads buried, electrical poles burnt, TV and Internet cables damaged, etc.— and are components of fixed infrastructure; they are relatively easy to quantify.

We would be remiss in future risk assessment if we ignored the loss of productive capacity or the economic loss due to a hazardous event, where businesses and people are unable to earn money.

For example, what would happen if a flow from Mauna Loa advanced down the flank of the volcano and entered the ocean? It is plausible that no homes would be impacted by such a flow, yet highways would be severed, commerce would be impeded, workers could not get to their jobs because travel would be disrupted. The loss of future earnings is harder to assess and has wide-ranging repercussions.

“Likelihood” is often incorporated into the term “hazard” in the risk equation. It is often expressed in terms of probability. Probability estimation is not an easy task and, for lava flow hazards, is based on lava flow ages. To do the best job, we need to determine the recurrence interval (RI) for all lava flows, and this requires access to all lands impacted by lava.

The RI is the average time between past lava flows. For example, in the 167 years since 1843, Mauna Loa has erupted 33 times; 167 years divided by 33 eruptions is about 5 years between lava flows.

Probability and recurrence interval vary inversely. The shorter the RI, the larger the probability that a lava flow will occur in a given period. In our example, the probability of a Mauna Loa eruption occurring in any one year is about 1/5 or 20 percent. Probability can be a difficult concept for many people to grasp. Geologic hazards are generally considered to be random events; there is an equal chance that it will occur in any given year. Passage of a significant amount of time since the last hazardous event does not necessarily mean that there is a greater chance of another one occurring.

Geologic hazards are a reality of living on the flanks of active volcanoes. It is important to know what those hazards are. Risks can be reduced by being prepared and planning for hazardous events. Furthermore, land use planning is the most effective tool for mitigating lava flow hazards. All in all, living on the flanks of volcanoes can be a risky business.

Kilauea Activity Update

Over the past week, activity on the east rift zone flow field remains focused on the construction of low shields. This activity was located well above the Pulama pali, over the breakout point of the Quarry flow. Weak activity continues along the Quarry flow itself from the top of the pali to the coastal plain. In addition to that lava erupting and flowing through the TEB and Quarry flow tube systems, lava is also erupting from two vents within Pu`u `O`o. These vents are slowly filling Pu`u `O`o’s crater, and the Webcam on Pu`u `O`o has been providing spectacular views both day and night.

At Kilauea’s summit, a circulating lava pond deep in the collapse pit within the floor of Halema`uma`u Crater was visible via the Webcam throughout the past week. The baseline lava level continues to rise slowly and was punctuated a few times by short-lived lava-level increases that brought the lava surface to its highest level yet recorded. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

No earthquakes beneath Hawai`i Island were reported felt during the past week.

Visit the HVO Web site for detailed Kilauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call (808) 967-8862 for a Kilauea summary; email questions to askHVO@usgs.gov.

Volcano Watch is a weekly article and activity update written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.

NetQuakes Offer Community Partnering in Seismic Monitoring

Wednesday, April 14, 2010, 7:37 a.m., Hawaii Standard Time: “Uh. Oh, oh. Did you feel that? It felt like an earthquake.”

By now, many people are familiar with U.S. Geological Survey (USGS) earthquake reporting utilities. First, there’s the Earthquake Notification Service that sends email to lists of subscribers. Messages are sent according to user profiles specifying regions of interest, earthquake magnitude or size, and even times of day when a user wishes to receive an earthquake email notification.

There are also the USGS “recent earthquakes” Web pages that can be accessed via earthquake.usgs.gov/earthquakes or, simply, earthquake.gov. These Web pages show earthquake times and locations, as determined by the USGS or its seismic network cooperating partners in different parts of the United States and the world.

To display the effects of significant earthquakes, the USGS has developed a family of earthquake information products related to its ShakeMap software. Within minutes of a significant earthquake, ShakeMap provides maps of strong ground shaking and shaking intensity that are used to help guide earthquake response and recovery. ShakeMaps are also used as input to post-earthquake impact assessments and, even long after the actual event, as tools for earthquake preparation and response planning.

Separate but complementary to ShakeMaps are the Community Internet Intensity Maps, or “Did You Feel It?” maps. Using information collected via a Web questionnaire about earthquake effects, these maps graphically show the distribution of damage and other earthquake effects. After a large earthquake, the volume and density of “Did You Feel It?” information submitted by the general public are great compared to the number of instrumental recordings. “Did You Feel It?” reports are incorporated into ShakeMaps.

While combining “Did You Feel It?” and ShakeMap has proven to be quite effective, the USGS would like to have better instrumental recordings of strong earthquakes with increased numbers of modern instruments. This has resulted in a recently launched project called NetQuakes.

The NetQuakes project uses new and relatively low-cost digital seismographs that report data to the USGS via the Internet. These seismographs have been designed to be installed in private homes, businesses, public buildings and schools where there is an existing broadband Internet connection.

At the heart of the NetQuakes project are people who are willing to host the NetQuakes seismographs, which access the Internet via a wireless router connected to the hosts’ existing broadband Internet connection. The seismographs transmit data only after earthquakes above about magnitude 3 have been recorded and otherwise do not consume any significant bandwidth.

The USGS is focused on getting large numbers of NetQuakes instruments installed in high-hazard urban areas like San Francisco, Los Angeles or Seattle, but the Hawaiian Volcano Observatory (HVO) has received a small number of NetQuakes seismographs to use in Hawai`i. We have found a number of hosts and have begun to install the NetQuakes instruments.

Following the magnitude-3.8 earthquake on Wednesday morning, April 14, our first NetQuakes record was automatically retrieved and posted online. This came from our host in Honomu, where, because of the high mountains, it is challenging and costly for us to retrieve data from instruments using our typical means of data transfer. As we expand the NetQuakes footprint, we expect to record additional data that will help us better understand the distribution of earthquake effects. In Hawai`i, we look forward to being able to deploy a larger number of NetQuakes seismographs.

Wednesday’s earthquake was a lithospheric adjustment to the weight of the island. The USGS received 127 “Did You Feel It?” reports on the earthquake, which was felt across the Island of Hawai`i.

Kilauea activity update

On Kilauea’s east rift zone, breakouts along the east margin of the Thanksgiving Eve Breakout (TEB) flow remain active on the Pulama pali. The active flow front was just a few hundred yards from rejoining the main TEB flow field on the coastal plain on Thursday, April 15. If lava supply to these flows continues, they are expected to migrate south along the east margin of the TEB flow field, near the public viewing area. The flows may also stall before reaching the coast due to ongoing lava supply fluctuations.

At Kilauea’s summit, a ponded, circulating lava surface deep within the collapse pit inset within the floor of Halema`uma`u Crater was visible via Webcam during much of the past week. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

One earthquake beneath Hawai`i Island was reported felt during the past week. The magnitude-3.8 earthquake occurred at 7:37 a.m., H.s.t., on Wednesday, April 14, 2010, and was located 4 km (2 miles) west of Pahala, at a depth of 38.2 km (23.7 miles),

Visit the HVO Web site for detailed Kilauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call (808) 967-8862 for a Kilauea summary; email questions to askHVO@usgs.gov.

Volcano Watch is a weekly article and activity update written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.