November 18, 2004
A weekly feature provided by scientists at the Hawaiian Volcano Observatory.
Designing new eyes for monitoring volcanoes
Scientists have all sorts of ways to remotely monitor volcanoes. Here at Hawaiian Volcano Observatory, for example, we use seismometers, GPS receivers, and tiltmeters to study ground movements, and spectrometers and other sensors to look at volcanic gas emissions. In some situations, though, there is simply no substitute for the human eye when monitoring a volcano, especially when the volcano is in eruption.
Volcanoes can be hard to study up close and in person. Because it may be days, weeks, or even years between important events, it isn't always possible to have observers on the ground. In addition, volcanoes are often inaccessible due to their remote location and/or harsh environmental conditions. When you throw an eruption into the mix, another level of complexity is added to what may be an already difficult and dangerous situation.
For these reasons, scientists at Hawaiian Volcano Observatory have, for years, built camera systems to act as surrogate eyes, and, with the rapid advances in digital camera technology, these eyes are seeing better and better. Many of you are probably already aware of the video camera perched on the rim of Pu`u `O`o taking near-real-time pictures of the crater floor. Go to http://hvo.wr.usgs.gov/cam to check out current conditions and activity at the Pu`u `O`o crater and see this camera in action.
This video-camera system was expensive to build and time-consuming to install. Thus, it was placed in a location where there is little likelihood that it will be destroyed. But for those situations where destruction of the camera system is possible, even probable, Hawaiian Volcano Observatory scientists have begun designing cheap, expendable camera systems that are easy to build and can be set up by a single person in just a few minutes. This reduces the potential monetary loss and minimizes the time that scientists are exposed to dangerous conditions.
We have been testing such a camera system on the southern flank of the Pu`u `O`o cone for the last several months. This camera overlooks the MLK and PKK vent areas and has captured dozens of breakouts from these vents. This has helped Hawaiian Volcano Observatory scientists keep track of the timing and location of these events as well as monitor ground subsidence and collapse in the Puka Nui area on the southwest side of Pu`u `O`o. If the ongoing unrest at Mauna Loa begins to pick up and an eruption looks imminent, it's likely that at least a few of these camera systems will be watching.
When Mount St. Helens reawakened this fall, scientists at the Cascades Volcano Observatory asked us to build a camera system to help them monitor the eruption. A few simple modifications to our current design resulted in a camera that has been capturing images of the growing lava dome in the crater at Mount St. Helens since early October.
Operating the camera system in the harsh winter conditions of Mount St. Helens, however, has provided unique challenges. For on thing, thick ice forms on the camera enclosure, blocking the camera's view. This problem was surmounted by putting a heater, powered by a small wind generator, in a stovepipe below the enclosure. The rising heat melts any ice accumulated on the enclosure.
High winds on Mount St. Helens have also done their damage. The bracket that attaches the camera enclosure to a tripod is, in turn, attached to the enclosure using an industrial-strength structural adhesive. For conditions at Kilauea, this works fine - at Mount St. Helens, it does not. The adhesive failed, and the camera blew off the tripod, thus providing a close-up view of snow and gravel. This was easily fixed by substituting bolts for glue.
As winter envelopes the Pacific Northwest and buries the Cascades, we face at least one more challenge - several feet of snow. When the inevitable happens, we know of only one sure solution - wait for spring and hope the camera is still there.
Eruptive activity at Pu`u `O`o continues. The PKK flow continues to host scattered breakouts from near the top of Pulama pali to the coastal plain. The new ocean entry at east Lae`apuki, 3.6 km (2.2 mi) from the end of the pavement on Chain of Craters Road in Hawai`i Volcanoes National Park, remains active. Expect a 2 to 2.5 hour walk each direction and remember to bring lots of water. The new lava delta is about 190 m (623 ft) long (parallel to shore) and 57 m (187 ft ) wide. Remember, deltas can collapse without warning! Stay well back from the sea cliff, heed the National Park warning signs, and don't even think about descending onto the growing delta. The eruptive activity in the crater of Pu`u `O`o remains weak, with several spatter cones glowing but not doing much else.
During the week ending November 17, there was one earthquake felt in Waimea at 9:06 am on November 16.
Mauna Loa is not erupting. The summit region continues to inflate slowly. Seismic activity continues at an elevated level. 188 earthquakes were recorded beneath the summit area during the period November 10-18. Nearly all are 40 km (23 miles) or more deep and are the long-period type with magnitudes less than 3.
Visit our web site (hvo.wr.usgs.gov) for daily volcano updates and nearly real-time earthquake information. Visit the Cascades Volcano Observatory (CVO) web site (Vulcan.wr.usgs.gov) for Mount St. Helens updates.
Updated: November 22, 2004 (pnf)