MEDIA RELEASE

On March 19, 2008, an explosion within Halema`uma`u Crater heralded the start of a new eruption, the first at Kilauea`s summit since 1982.

Surprisingly, this eruption was not preceded by traditional indicators, such as earthquakes and ground swelling. Also unusual, Kiauea`s new summit eruption occurred without interrupting activity on the volcano`s east rift zone, which has been erupting nearly nonstop since 1983.

Although lava is frequently visible deep within the summit vent, it has not erupted significant amounts of ash or spatter. Instead, it has emitted great quanitities of volcanic gas, creating a major impact on Hawai`i Island`s air quality.

On the second anniversary of this unique eruption, Hawaiian Volcano Observatory volcanologist Mike Poland explores its possible causes, and discusses how Kilauea`s summit eruption might evolve in the months and years to come. The program starts at 7 p.m. Tuesday (March 16) at the Kilauea Visitor Center auditorium.

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.) 

Surface flows have been active on Pulama pali within the Royal Gardens subdivision and on the coastal plain west of the subdivision. There has been little forward advancement toward the ocean, however, due to last week’s disruption in lava supply caused by a deflation/inflation (DI) event at Kilauea’s summit.

Rapid deflation at Kilauea’s summit started again on Thursday and will probably lead to a slow-down in surface activity. When the volcano reinflates, there will likely be a corresponding increase in surface activity on the pali as the system recovers.

At Kilauea’s summit, a spattering and roiling lava surface, deep within the collapse pit inset within the floor of Halemaumau Crater, was visible via Webcam. For much of the week, the lava surface was seen to cyclically rise and fall.

This behavior may stop as the lava surface lowers in response to the ongoing DI deflation, and may start again when the volcano reinflates. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

One earthquake beneath Hawaii Island was reported felt during the past week.

A magnitude-3.4 earthquake occurred at 10:41 a.m. Tuesday, Feb. 23, and was located 8 km (5 miles) southeast and offshore of Kalapana at a depth of 44 km (28 miles).

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

The changing vapors. (Photo courtesy of Hawaiian Volcano Observatory)

Several factors affect the plume’s appearance. Changes in physical conditions at the vent, meteorology, and even chemical reactions occurring as gas boils out of the melt can conspire or act alone to produce the variably visible plume.

The summit plume is principally composed of water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2), all of which are clear and colorless gases. The visible part of the plume includes a minor amount of ash, along with a suspended mixture of tiny droplets and particles, called aerosol. Volcanic ash consists of rock dust and glass particles less than 2 mm (0.08 inches) in diameter.

The aerosol in the plume is even smaller, less than 0.0025 mm (0.0001 inch) in diameter — about one-tenth the diameter of a strand of human hair. Aerosol is composed chiefly of dilute sulfuric acid (H2SO4), formed when SO2 reacts in the presence of oxygen and water vapor.

Physical changes occur intermittently at Halemaumau as the unstable rim crumbles and releases rocks and debris into the vent. These rockfalls disturb the top of the magma column and sometimes result in the production of brief ash-rich plumes, ranging from gray to brown, before returning to their prior appearance.

Meteorological variations, including relative humidity, temperature, cloud cover, and wind speed also affect plume appearance. Because the plume is visible, owing partly to the presence of water-laden droplets, air temperature and relative humidity work in concert to changing the plume’s visibility. Higher humidity and lower temperature conditions cause moisture condensation, producing a more visible plume.

The converse temperature/humidity story is true, as well. Increasing wind speed tends to make the plume more compact, and usually more opaque, except at very high wind speeds.

Cloud cover diffuses the sun’s rays; diffuse sunlight is scattered in a way that appears different to our eyes than does direct sunlight. The result of this effect can be that a plume appearing blue and translucent in bright sun light, turns milkier and denser under heavy cloud cover.

Chemical transformations occurring with the plume are of great interest with respect to their effects on plume appearance. These same changes also provide clues about processes occurring at the top of the summit magma column, a place often not directly visible from the surface.

As noted earlier, the visible aerosol is comprised of H2SO4, formed by chemical oxidation of SO2. A primary factor accounting for variability in the amount of H2SO4 produced is obviously the amount of SO2 bubbling out of the magma to start with, but the temperature of the vent has a strong effect, as well. Higher temperatures within the vent tend to oxidize more SO2.

A useful lesson showing the complex effects of temperature and chemistry on the visibility of SO2- and H2SO4-bearing plumes occurred at coal-fired power plants on the mainland in the 1990s. Power companies worked hard to clean up sulfur and nitrogen oxide emissions by installing chemical scrubbers.

The scrubbers reached their goal of effectively decreasing the amount of clear, colorless and noxiously polluting SO2 in their exhaust gases, but, partly because of gas temperature and humidity effects, had the unintended consequence of producing dense blue plumes containing light-scattering H2SO4.

The experience of the power stations underscores the importance of temperature and humidity on plume visibility. It also demonstrates how decreases in SO2 emissions do not always result in a less visible plume. Conversely, a more dense plume doesn’t necessarily mean more SO2, either.

At Kilauea, we confirmed this lesson by using ultraviolet spectrometers to measure SO2 emission rates of dense white plumes and thin, wispy blue ones. We’ve found that plumes appearing thin and wispy often contain as much or more SO2 then dense white ones.

A substantial and valuable part of the science of volcanology is based on simple but careful observations. Combining these direct observations with instrumental ones has helped volcanologists answer numerous questions about how volcanoes work. As our toolbox of high-tech methods bulges, we remind ourselves of the value and place of simple human-based observations.

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.) 

Surface flows have been active within and adjacent to the Royal Gardens subdivision. While some of these flows have been located on the pali, most of the activity has been focused on the coastal plain within about 1 km (3,300 ft) of the base of the pali.

Lava flows remained active despite back-to-back deflation/inflation (DI) events during the week at Kilauea’s summit, though variations in surface activity did occur in response to the DI events.

At Kilauea’s summit, a spattering and roiling lava surface, deep within the collapse pit inset within the floor of Halemaumau Crater, was visible via Webcam. The depth to the lava surface varied in response to the DI events, lowering during the deflation phase and rising slightly during inflation.

Overprinted on these broader changes were periods of repeated and relatively rapid rise and fall of the lava surface. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

No earthquakes beneath Hawaii Island were reported felt during the past week.

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.) 

Surface flows have been active on the lower pali and coastal plain within the Royal Gardens subdivision. These flows have largely stayed close to the base of the pali but had extended halfway to the coast by Thursday morning.

A deflation/inflation cycle, which started on Tuesday at Kilauea’s summit, caused these flows to slow down by mid-week. Surface flows in the same general area will likely be renewed when the volcano re-inflates.

At Kilauea’s summit, a spattering and roiling lava surface, deep within the collapse pit inset within the floor of Halemaumau Crater, was sporadically visible via Webcam. On several occasions, the lava surface rose slightly briefly covering the floor of the pit, but activity, for the most part, has remained fairly steady.

Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

There were no felt earthquakes during the past week.

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.) 

Surface flows have been active above and within the Royal Gardens subdivision. By midweek, lava had crossed through the western part of Royal Gardens and had reached the base of the pali.

A deflation/inflation cycle at Kilauea’s summit, however, started on Tuesday and may cause these flows to slow or stop. Surface flows in the same general area will likely be renewed when the volcano re-inflates.

At Kilauea’s summit, the lava surface deep within the collapse pit, inset within the floor of Halemaumau Crater, was sporadically visible via webcam. The deflation phase of the deflation/inflation cycle caused the lava to retreat to a deeper level, but it will likely rise again after the volcano begins to inflate. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

Two earthquakes beneath Hawaii Island were reported felt during the past week.

A magnitude-3.5 earthquake occurred at 9:06 p.m. Monday, Feb. 1 and was located 1 mile northwest of Pahala at a depth of 23 miles.

A magnitude-2.7 earthquake occurred at 4:13 p.m. Tuesday, Feb. 2, and was located 16 miles northwest of Kailua-Kona at a depth of 22 miles.

On Wednesday morning, several Kona residents reported feeling vibrations that were not associated with an earthquake, but which may have been produced by a meteorite, according to the Infrasound Laboratory of the University of Hawaii (www.isla.hawaii.edu).

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

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.) 

Surface flows have been active near the top of the pali within and just above the Royal Gardens subdivision. The westernmost of these flows was slowly moving downslope along Alii Avenue and had reached down to about the 1400-ft elevation by Wednesday.

Another deflation/inflation cycle at Kilauea’s summit also started Wednesday, and may cause the surface flows to slow or stop. Surface flows in the same general area above the pali will likely start again when the volcano re-inflates.

At Kilauea’s summit, the lava surface deep within the collapse pit, inset within the floor of Halemaumau Crater, was visible via webcam. The deflation phase of the deflation/inflation cycle caused the lava to retreat to a deeper level, but will likely rise again after the volcano begins to inflate. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

One earthquakes beneath Hawaii Island was reported felt during the past week. A magnitude-3.0 earthquake occurred at 2:37 p.m. Monday, Jan. 25 and was located 2 miles west of Pahala at a depth of 23 miles.

Visit the HVO Web site (hvo.wr.usgs.gov) 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.

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

Surface flows were active above the pali through the first part of the week. One of these flows reached down into the Royal Gardens subdivision before the deflation phase of another deflation/inflation cycle at Kilauea’s summit caused all the surface flows to slow or stop. Surface flows in the same general area above the pali will likely start again when the volcano re-inflates.

At Kilauea’s summit, the lava surface deep within the collapse pit inset within the floor of Halemaumau Crater was visible via webcam early in the week. The deflation phase of the deflation/inflation cycle caused the lava to retreat to a deeper level, and, as a result, night-time glow above the vent was relatively weak by mid-week.

Lava is expected to rise back into webcam view after the volcano begins to inflate. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

Three earthquakes beneath Hawaii Island were reported felt during the past week.

A magnitude-3.0 earthquake occurred at 7:34 a.m. Friday, Jan. 15 and was located 2 miles southwest of Kilauea summit at a depth of 9 miles.

A magnitude-3.1 earthquake occurred at 12:02 p.m. Monday, Jan. 18, and was 4 miles southwest of Kawaihae at a depth of 6 miles.

A magnitude-4.3 earthquake occurred at 1:01 p.m. the same day and was 4 miles northwest of Pahala at a depth of 4 miles.

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

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

This has been a quiet week on Kilauea’s east rift zone, with no sign of lava erupting from the TEB vent. Puu Oo had begun to re-inflate as of this writing (Thursday, Jan. 14), and may result in new surface flows above the pali as portions of the lava tube become reoccupied.

At Kilauea’s summit, a prolonged deflation through the first half of the week was accompanied by a withdrawal of lava to a deeper level. As a result, night-time glow above the collapse pit inset within the floor of Halemaumau Crater was relatively weak.

The glow became brighter during the second half of the week, however, as the summit began to re-inflate and lava rose back up to a shallower level in the pit. After the lava rose back into view, the Webcam revealed a churning and spattering lava surface often with minor fluctuations in height. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

One earthquake was felt this past week. A magnitude-3.1 earthquake occurred at 8:27 p.m. Wednesday, Jan. 13 and was located 17 miles west of Kawaihae at a depth of 14 miles.
Visit the HVO Website (hvo.wr.usgs.gov) for detailed Kilauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call 967-8862 for a Kilauea summary; email questions to askHVO@usgs.gov.

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

Lava stopped entering the ocean entry at the Waikupanaha, west of Kalapana, early last week as the lava supply from the TEB vent dwindled. Small lava flows were active above the pali starting mid-week.

Glow above the collapse pit inset within the floor of Halemaumau Crater, at Kilauea’s summit, has been bright at night from the Jaggar Museum this past week.  The lava surface deep within the collapse pit has been fluctuating in height, episodically rising up to form a small lava pond at the bottom of the pit.

This activity has been visible, primarily at night, in the Webcam perched on the rim of Halemaumau.  Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.

One earthquake beneath Hawaii Island was reported felt during the past week. A magnitude-1.8 earthquake occurred at 10:22 p.m. Wednesday, Jan. 6, 2010, and was located 4 miles east of Captain Cook at a depth of 5 miles.

Visit the HVO Web site (hvo.wr.usgs.gov) 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 written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

Kilauea has been erupting nearly continuously for 27 years as of Sunday, Jan. 3, 2010.

The eruption has gone through many changes in those years, most notably in 2008 with the addition of a second vent and degassing source. While this change made the list of top 10 news stories in 2008, it failed to make the grade in 2009 with the tanking national economy, state and county budget woes, and other more immediate concerns taking top honors.

On a longer time scale, the eruption of Kilauea, or any Hawaiian volcano, is a big deal—in both positive and negative ways. Eruptions destroy structures encourage the tourism industry on Hawaii Island.

While providing abundant land to develop, the threat of destruction by active lava flows affects insurance and mortgage issues, increasing development costs. Eruptions can produce rich soil that supports agricultural products, but also emit vog and volcanic gases that damage crops growing in the volcanic soil.

Hawaiian volcanoes pervade nearly every aspect of our lives. For starters, we would be treading water in the middle of the Pacific Ocean if it weren’t for several million years of volcanic activity building islands that provide perpetual footrests.

The soils in which we grow crops and gardens are derived from weathered lava and tephra. Volcanic soils are known worldwide as being rich and well suited for everything from taro to sugar cane, pineapples, and coffee. The needed water is obtained from rainfall scraped from passing clouds by high volcanic ridges.

Living on an active volcano presents many concerns, most of which have been realized to some extent in the past 27 years of Kilauea’s eruption. Lava flows have ignited forest fires and destroyed many structures, subdivisions, and towns, displacing small populations.

At the same time, thousands to millions of tourists have been drawn to Kilauea hoping to witness to Pele’s activity. Roads have been blocked and ground traffic rerouted while air tour traffic has increased.

Many Hawai`i Island residents realized first-hand how much of the volcanic gas emissions were going out to sea from Puu Oo vent when a second degassing source in Halemaumau Crater opened in early 2008. The location of the new vent directed its emitted gases along the southern part of Hawaii Island before being blown offshore.

Over the history of humankind, our conflicted relationship with volcanoes has, on the one hand, inspired artists and authors (to be detailed in January Volcano Watch columns) and deity worship (Pele, in Hawaii) while wreaking local destruction, and, in extreme cases, death.

To explore all of these aspects of Hawaiian volcanoes, HVO and our partners have organized a number of educational and experiential activities during January 2010, which is designated as “Volcano Awareness Month.”

The “eruption” of volcano awareness activities begins with a kick-off event in Hawaii Volcanoes National Park on Jan. 2 A calendar of daily Volcano Awareness Month events in January, as well as a wealth of information about Hawaiian volcanoes, can be found in the insert and on the HVO Web site at http:// hvo.wr.usgs.gov

Hawaii is volcanoes and, during Volcano Awareness Month, we encourage you to learn more about this fundamental aspect of our island.

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

Clear weather and an active lava column in the Halemaumau Overlook vent this week is brightening the nighttime glow at the summit of Kilauea just in time for the holiday season. The glow is especially notable from the Jaggar Museum viewing area in Hawaii Volcanoes National Park, located only 1.2 mile from the vent.

Activity in the summit vent is following a pattern observed many times in 2009. Early this past week, lava in the vent went through a series of impressive filling and draining cycles that lit up the base of the gas plume with incandescent glow. One filling and draining cycle took about 5 minutes to complete.

At this high stand of lava, small plates of cooled crust would form around the edges of the pond. As the lava flowed back into the opening during the drainback phase of the cycle, the cooled crust pieces moved toward the center of the opening and disappeared down into the vent. The draining created a chaotic area of spattering at the center of the pond.

Similar to earlier episodes, the draining phase happened faster than the filling phase. During both filling and draining the sounds of lava sloshing and spattering were quite loud, and, when the draining was finished, there was a quiet period lasting tens of seconds. During this quiet period the vent went fairly dark compared to the very bright levels during active filling and draining.

This activity was captured on video by scientists making routine observations and measurements early this past week from directly above the Overlook vent, and can be viewed on the Web site of the Hawaiian Volcano Observatory.

For images and video of Kilauea’s activity, visit the following Web page: hvo.wr.usgs.gov/kilauea/update/images.html

The vent continues to release between 700 and 1,000 tonnes of sulfur dioxide gas each day as the height of the lava column in the vent remains more than 660 feet below the foor of Halemaumau Crater and 950 feet below the crater rim.

The nighttime glow from the Overlook Vent varies considerably from hour to hour and week to week as the height of the lava column changes and the size of the opening above the column is altered by the accumulation of cooled lava and spatter and collapse of the material into the churning lava.

Thus, at the time of this writing (Wednesday evening), the glow was a little subdued compared to earlier in the week, but beautiful at sunset nonetheless! Be sure to bring warm clothes if you plan to visit the Jaggar Museum at night!