Volcano Watch — An alert to changes in HVO's web updates

Currently, HVO scientists produce updates by scanning available information, summarizing the activity, and writing the updates directly to the HVO website. The updates are daily for Kīlauea, weekly for Mauna Loa, and biweekly for Anatahan.

National focus on natural hazards has produced another audience for our updates -natural hazards national websites. Next week, the Volcano Hazards Program webmaster, Dina Venezky, will enable us to post our updates automatically to both local and national websites. Ho-Hum, you say? Wait, there's more!

The content of our updates for Kīlauea and Mauna Loa will now include a common alert level. This is a four-level system where each level is indicated by a word (Normal, Advisory, Watch, Warning like the National Weather Service) and a color (Green, Yellow, Orange, Red in the order of increasing severity). In most cases, the word and color will indicate the same level, although the colors are meant to focus on aviation hazards only.

A Normal and Green level indicates that a volcano is at a background level of activity. The Advisory and Yellow level indicates that a volcano is showing signs of "elevated unrest, above known background level." Of course, the trick to Yellow is defining what "known background level" is.

Mauna Loa is at the "Advisory and Yellow" level, based on its accelerated inflation and unusual seismicity over the past two years, even though it currently is only slowly inflating and has few earthquakes. We are still watching it closely.

The Watch and Orange level indicates that a volcano shows signs of heightened or escalating unrest, with increased potential for eruptive activity. That status also covers a volcano that is in eruption but poses limited or local hazards. This one was written with Kīlauea's current eruption in mind. The ongoing eruption poses hazards only near the eruption site, so Kīlauea is in "Watch and Orange" status.

The Warning and Red level is reserved for volcanoes when an eruption is forecast to be imminent or when a hazardous eruption is underway. The color part of the uniform alert level is only focused on the possibility that the eruption will pose a hazard to aircraft, that is, whether the eruption will produce ash in the atmosphere. Kīlauea's current eruption does not produce ash in the atmosphere, so it is not considered a "Warning and Red" type of eruption.

All of these changes are aimed at bringing HVO into compliance with practices of the other four volcano observatories. They will make it easier for pilots flying aircraft over large regions to get a quick update on the possibilities of encountering ash or being diverted because of ash from any volcano along an entire flight route. Flying into volcanic ash can cause a jetliner to lose the thrust of its engines quickly - not a good thing.

Coincident with, but not caused by, these changes, will be a change in the personnel posting the updates. July 17th will be the last day that HVO's intrepid morning observer, former Scientist-in-Charge Don Swanson, will post the Kīlauea update. After doing it for six years, Don has decided it's time for a change. All of us who enjoyed and learned from his rich and articulate updates and pictures owe Don profound thanks for those 2000+ pearls of volcano wisdom.

The Kīlauea updates will continue to be posted daily by HVO staff members on a rotational schedule. The bad news is that they won't be written by Don. The good news is that it will be an opportunity to hear other voices. Thanks, Don, for taking us this far and showing us the way.

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Volcano Activity Update

This past week, activity levels at the summit of Kīlauea Volcano have remained at background levels. The number of earthquakes located in the summit area is low (usually less than 10 per day that are large enough to locate). Widening of the summit caldera, indicating inflation, has resumed after pausing earlier in April.

Eruptive activity at Pu`u `O`o continues. On clear nights, glow is visible from several vents within the crater. Lava continues to flow through the PKK lava tube from its source on the flank of Pu`u `O`o to the ocean, with surface flows breaking out of the tube at the 2,300-2,200-ft elevation. The most persistent of these flows is the "Campout breakout," which had advanced to the 500-600-ft elevation last week.

Lava is still entering the ocean at East Lae`apuki, in Hawai`i Volcanoes National Park. The lava bench continues to grow following the major collapse of November 28, 2005, and is now approximately 1,100 m (3,600 ft) long by 350 m (1,150 ft) wide, with a total surface area of 22 ha (54 acres) last week.

Access to the sea cliff near the ocean entry is closed, due to significant hazards. The National Park has reopened the surrounding area, however. If you visit the eruption site, check with the rangers for current updates, and remember to carry lots of water when venturing out onto the flow field.

There was one earthquake beneath Hawai`i Island reported felt within the past week. A magnitude-1.4 earthquake occurred at 5:03 p.m. H.s.t. on Sunday, July 9, and was located 15 km (9 miles) northeast of Pahala at a depth of 4 km (2 miles).

Mauna Loa is not erupting. During the past week, earthquake activity remained low beneath the volcano's summit (no earthquakes were located). Extension of distances between locations spanning the summit, indicating inflation, continues at slow rates.