Volcano Watch — HVO looks to European colleagues for new strategies to track and model lava-flow hazards

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The purpose of the workshop was to explore the development of (1) automated satellite systems to detect volcanic eruptions and track lava flows, and (2) computer programs to forecast where future lava flows might go. Experts from several academic institutions and volcano observatories around the world shared progress reports and plans for future developments from each of their agencies or departments.

At HVO, infrared satellite imagery is routinely used by geologist Matt Patrick, who presented his methodology at the French workshop. If you have followed the lava flows erupted from Pu‘u ‘Ō‘ō during the past year, you've probably seen some satellite views of Kīlauea's lava activity on HVO's website. These infrared images, which show heat radiating from the ground, are ideal for identifying active lava flows.

The two main impediments to routine use of infrared satellite imagery are the infrequency of high-resolution image acquisition and the presence of clouds. As a rule, low-resolution imagery is available many times per day via the GOES weather satellite (www.goes.noaa.gov). But satellite imagery with resolution high enough to map lava flows is available only a few times per month—and if these rare images are partially or wholly obscured by clouds, that opportunity to map lava flow positions is missed. An additional drawback is that the higher-resolution images are not available until 2-3 days after acquisition, which is not optimum for tracking hazardous lava flows.

At the workshop, participants investigated the coupling of satellite detection and tracking with computer simulations of advancing lava flows. Imagine a system that automatically detects new volcanic eruptions and forecasts potential lava flow paths and advance rates. This is a worthy goal!

Developers and users of at least eight different lava-flow computer simulations have made great progress recently and presented their results at the workshop. Our interest was in seeing whether any of this software might be useable on Hawaiian volcanoes.

To date, HVO has not used computer simulations for eruption crises because the simulations focus on ‘a‘ā flows. Instead, we have employed simpler methods to forecast lava flow paths and to estimate potential lava flow advance rates. A good example of our approach is HVO's 2007 assessment of Pu‘u ‘Ō‘ō lava flow hazards north of Kīlauea's East Rift Zone. These simple methods address the most pressing problems and can be applied well before an emergency occurs.

But lava flow simulation software can be very useful for other purposes, such as hazard education. Observing a simulated lava flow as it moves down the side of a volcano is a learning experience, not to mention an entertaining one. Simulations are also useful for assessing how far downhill ‘a‘ā flows produced by hypothesized eruption rates will advance.

Even with the most accurate lava-flow simulation program, HVO would encounter significant uncertainty with its use. The most important input needed for effective lava flow forecasting is the rate at which lava is being erupted. But during the early hours or days of Hawaiian eruptions—the time at which these data are needed the most—this rate is extremely difficult to measure.

Improved measurement of eruption rate is an ongoing effort at HVO. We can use several different methods to estimate eruption rates, but each requires different conditions, and none can be used routinely. While these methods are helpful for monitoring the ongoing East Rift Zone eruption on Kīlauea, they will be crucial for tracking lava flows from Mauna Loa when it next erupts.

HVO appreciated the opportunity to work with the international volcano community on processes to detect and map advancing lava flows and forecast future lava flow paths. These new strategies could enhance future volcano monitoring efforts in Hawai‘i.

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Volcano Activity Update

A lava lake within the Halema‘uma‘u Overlook vent produced nighttime glow that was visible from the Jaggar Museum overlook and via HVO's Webcam during the past week. The lava lake rose and fell between about 50 and 70 m (165–230 ft) below the crater floor, synchronously with cycles of deflation and inflation (DI events) at Kīlauea's summit.

On Kīlauea's East Rift Zone, breakouts from the Peace Day tube remain active on the pali and on the coastal plain. Small ocean entries are active on both sides of the Hawai‘i Volcanoes National Park boundary. The Kahauale‘a II flow, fed from a spatter cone on the northeast edge of Pu‘u ‘Ō‘ō crater, continues to spread at the northern base of the Pu‘u ‘Ō‘ō cone.

No earthquakes were reported felt in the past week across the Island of Hawai‘i.