(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 along the west edge of the subdivision. The flows have advanced very little across the coastal plain over the past week and are about 1.7 km (1 mile) from the ocean.

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 lava surface rose to a slightly higher level early in the week as the volcano reinflated following last week’s deflation.

With the higher lava level, the lava surface was occasionally seen to cyclically rise and fall over periods of several minutes. 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.

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.

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

May 22, 2010, marks the 50th anniversary of the 1960 magnitude-9.5 Chilean earthquake, which was the largest earthquake worldwide in the last 200 years or more. But, for Hawaii residents, this great earthquake is rarely far from memory, due to the destructive tsunami it triggered, which killed 61 people in Hawaii and 122 in Japan.

An early reminder of this anniversary came in the form of a magnitude-8.8 earthquake that struck Chile in the early morning hours of Saturday, Feb. 27, 2010 (local Chilean time). Located approximately 230 km north of the 1960 earthquake, this event produced a modest tsunami that crossed the Pacific Ocean.

Luckily, in Hawaii, we experienced wave heights of only a few feet. However, in Japan, waves were high enough to flood several coastal towns.

Both the 1960 and the 2010 earthquakes occurred at the boundary between the Nazca and the South American tectonic plates. The two plates are converging at a rate of 70 mm (3 inches) per year as the Nazca plate is subducted beneath the South American plate. The relatively fast convergence is the reason why this region has a long history of large earthquakes and can expect to have more in the future.

From Chile, it takes about 15 hours for tsunami waves to reach Hawaii and about 22 hours to reach Japan. Thus, local authorities have ample time to warn residents and prepare for the approaching waves. If used wisely, this lead time allows for orderly evacuations of low-lying areas, as demonstrated by the smooth response to the Feb. 27 tsunami warning.

There was also ample time for evacuation in Hawaii on May 22, 1960, as the tsunami traveled across the Pacific Ocean. At 6:47 p.m., Hawaiian standard time, the U.S. Coast and Geodetic Survey issued an official warning that waves were expected to reach Hilo around midnight. At 8:30 p.m., coastal sirens in Hilo sounded and continued to sound intermittently for 20 minutes.

Many people heeded the warning and evacuated, but some did not, and when the first wave arrived just after midnight, hundreds of people were still at home on low ground in Hilo.

Because the first waves were only a few feet (1-2 m) high, many people returned to Hilo, thinking that the danger had passed. But the highest wave of the tsunami struck shortly after that, at 1:04 a.m. May 23.

Just before midnight May 22, 1960, Jerry Eaton, a seismologist at the U.S. Geological Survey’s Hawaiian Volcano Observatory, and four companions set up instruments in order to measure the tsunami wave heights from the Wailuku River Bridge on Hilo’s bay front.

Their measurements show that the tsunami was a series of waves that occurred over a span of more than two hours, with the highest wave of about 4.3 m (14 ft) arriving just after 1:00 a.m.

These wave heights sound modest compared to the 15-m (50 ft) waves that surfers tackle on the north shores of Hawaii. Tsunami waves, however, are much different, and more dangerous, in that each wave can raise sea level for tens of minutes and can push an incredible amount of debris-filled water on land.

Tsunami size is controlled by how much an earthquake displaces the sea floor. So, small differences in earthquake location (closer or farther from the coast) and earthquake depth can have big effects on whether or not a tsunami will be generated — and how big it will be.

Magnitude can also make a difference. The 1960 earthquake released more than 10 times more energy than the 2010 earthquake, which may have contributed to the size of the 1960 tsunami.

The Feb. 27, 2010, Chilean earthquake was well-recorded by scientists around the globe and will likely be studied for years to come. This should lead to a greater understanding of how these large earthquakes occur and under what conditions they produce widespread, destructive tsunamis.

(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.

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

Alert observers of Kilauea’s ongoing summit eruption often note the changing character of the ever-present plume emerging from Halemaumau. Sometimes it’s energetic, sometimes its color is a visibly ash-rich grey or brown, and at other times the plume appears translucent, even wispy. What causes these variations?

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.

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

The magnetic field surrounding the Earth protects it and all living things upon it from charged particles ejected by the sun.

What creates this magnetic field? Scientists hypothesize that it is caused by a natural geodynamo deep within the Earth. An incredibly hot, molten metal mixture of iron and nickel is constantly moving around a solid iron core, generating a magnetic field.

As you might guess, a magnetic field produced by moving fluid metal is not static. The magnetic field, which has a magnetic north and south pole, has been changing throughout history — at times reversing directions with the south pole, moving in orientation, and even changing in intensity.

How do scientists know this? The Earth’s magnetic field is actually recorded in many types of rocks when they form. The study of this ancient magnetism is known as paleomagnetism. “Paleo” means old or ancient, so paleomagnetism means “old magnetism.”

By studying paleomagnetism, we can learn more about the Earth’s interior, this geodynamo, and even track the moving continents (plate tectonics) throughout time.

The best recorders of paleomagnetism are volcanic rocks, especially basalt. As a result, Hawaiian volcanoes have been the subject of many paleomagnetic studies. When hot lava pours out of a volcano (or magma flows just under the surface), it contains lots of tiny crystals. Some of these crystals, such as magnetite and hematite, are iron-rich minerals that can be easily magnetized.

For example, using a normal refrigerator magnet, you can pick up tiny pieces of iron, paper clips, and other metal objects, because these objects become magnetized. The same magnet doesn’t really do anything if you place it against a ceramic tile or plastic bottle, however, because the chemistry and structure of these materials don’t easily allow for magnetization.

As the lava or magma begins to cool, these tiny little crystals orient their own north and south poles in line with the Earth’s magnetic field, just as the iron filings become oriented when a refrigerator magnet is near them. These properties include a direction (both declination and inclination) and intensity; collectively these properties are known as the “moment.”

Once the lava has cooled even more—below about 550 degrees Centigrade (1,020 degrees Fahernheit) — the magnetic moments of the crystals are frozen. As long as the rock doesn’t heat up again, these minerals will retain the same magnetic moment from the time they are cooled.

Therefore, if a scientist were to find the magnetic moment and orientation of a rock, he or she is actually measuring the magnetic field that was surrounding the flow when it cooled!

The magnetic properties aren’t visible in a rock, the way olivine crystals or the large air pockets known as vesicles are visible. They can, however, be an incredibly useful tool when identifying flows or studying rocks.

For example, two lava flows next to each other can appear to be very similar.

Sometimes slight changes in color or the amount of vegetation growing on them will help distinguish them, but oftentimes, one needs to look for crystals, the amount of vesicles, or even analyze the chemistry. What if those are very similar, as well?

One more test can be the similarity of their magnetic properties. Since the direction of the magnetic field changes throughout geologic time, different flows, which formed at different times in history, have different magnetic characteristics preserved in them!

Therefore, two lava flows that are similar in all other aspects could be distinguished by the direction of their magnetization.

As paleomagnetic techniques improve, another application has arisen — paleomagnetism as a dating technique. Many scientists have collected massive amounts of data on the paleomagnetic moment throughout time by combining paleomagnetic measurements with dating techniques, such as radiocarbon, lead-lead, or argon-argon dating.

If paleomagnetic measurements can be obtained from a sample, they can be compared to the paleomagnetic properties of dated flows to help constrain the age of the sample.

Paleomagnetism provides one more technique to help scientists study the rocks around them and unravel the secrets of the Hawaiian volcanoes.

(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.

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

Long-time Kilauea Volcano watchers know the drill when the supply of magma to the active vent on the volcano’s east rift zone is interrupted — abandonment of the “old” lava tube system, breakout of new surface flows, an evolving tube network, and eventually a new ocean entry.

This drama is unfolding again as many small aa and pahoehoe flows spread through what is left of the Royal Gardens subdivision and move a short distance across the coastal plain.

The flows are providing sporadic, distant views of incandescent lava, glow, and burning vegetation from the Hawaii County viewing area in Kalapana.

These flows are the consequence of a temporary decrease in magma supply to the active vent, beginning Dec. 29 and lasting nearly six days. The decrease corresponded to a pronounced deflation of the summit and east rift zone area, followed by several days of only slight inflation as recorded by sensitive tiltmeters.

Scientists interpret deflation as an indicator of a relative decrease in magma supply and inflation as an increase in magma supply.

When the Dec. 29 deflation event began, lava was pouring into the ocean at Waikupanaha, and more than 1,000 people per day were visiting the Hawaii County lava viewing area. Within a few days, however, the entry shut off completely.

Lava stopped entering the ocean by Jan. 4, but some lava continued to move through the uppermost part of the tube system within about 3 km (2 miles) of the TEB vent.

The upper tube system lies within a complex series of rootless shields tens of meters (yards) tall that were built by thousands of overlapping small flows between November 2007 and February 2008.

Near the lower end of these rootless shields, the original tube system became blocked as the Waikupanaha entry shut off, forcing lava to break out onto the surface at several locations between the shields and the top of Royal Gardens.

These flows are slowly creating a new but unstable tube system as the supply of magma to the vent continues to fluctuate. Seven deflation-inflation events have occurred since Dec. 29.

During the inflation periods, new breakouts from the tube have generally formed longer flows that reached lower and lower elevations on the pali. Breakouts from the next inflation period often start lower than the previous breakout—evidence that the tube system was elongating and forming longer flows.

The overall result of this pattern, as described by scientists, is a “two steps forward, one step back”-style of flow advancement and tube development.

Continued small fluctuations in magma supply as a consequence of small deflation-inflation cycles will likely promote growth of the new tube system all the way to the coast, west of the Waikupanaha entry.

But a larger- or longer-than-usual deflation event may cause the young tube system to stagnate and trigger new breakouts above Royal Gardens in a sudden step backward.

(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.

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

In the early hours of Monday, Feb. 1 a swarm of microearthquakes began to occur on the south flank of Kilauea Volcano. The swarm started slowly, with only a few earthquakes per hour, and reached a peak of almost a dozen earthquakes per hour on that afternoon.

By Tuesday afternoon, approximately 40 hours later, it was over. In all there were 85-90 microearthquakes in the swarm, many of them too small for computing a high-quality location.

The earthquakes occurred in the central region of Kilauea’s south flank and were in a relatively narrow north-south streak, extending southward from Poliokeawe Pali. This region of the south flank has seen flurries of earthquake activity in the past, and these flurries have often been associated with a phenomenon known as a “slow earthquake.”

The term “slow earthquakes” describes a relatively recently identified process that was first documented for volcanoes in Hawaii and is also recognized at other locations. The Hawaii examples have all been located on Kilauea Volcano’s south flank.

A slow earthquake is almost identical to regular earthquakes: the island moves in response to sudden slip on a fault. The only difference is that instead of lasting just a few seconds, the event lasts for many hours. These are often also called “silent earthquakes,” because the slip does not excite seismic waves, thus there is no ground shaking. However, the earth movement can trigger many small regular earthquakes like those recorded this week.

Careful analysis of data by Hawaiian Volcano Observatory scientists indicate that between Sunday evening and Tuesday afternoon, the south flank indeed slipped southward. Stations that monitor ground motion include instruments that sense even very slight changes in ground tilt and Global Positioning System (GPS) instruments that measure three-dimensional changes in position.

Preliminary results from these stations suggest that the south flank moved at speeds up 16 feet per year — about 1.2 inches over two days.

This rate of ground motion is hundreds of times faster than the rate of the persistent slow slip of Kilauea’s south flank, which has been occurring at rates of about 3 inches/yr in at least the last few decades.

However, it still about a trillion times slower than the ground motion that occurs in a typical earthquake, where the full amount of slip happens within a few, to tens, of seconds. If the south flank slip that occurred on Monday-Tuesday had occurred all at once, it would have been a magnitude 5+ earthquake.

In the past 13 years, the eastern part of Kilauea’s south flank (Poliokeawe to Kalapana) has experienced at least six slow and five “fast” earthquakes with equivalent magnitudes of 5 or greater. The time interval between slow earthquakes has been increasing from about 750 days to almost 960 days between the two most recent ones.

Each slow earthquake was accompanied by a swarm of microearthquakes located in north-south streaks (why they piqued our interest when they occurred in the same pattern this past week).

Close study of the slow earthquake and swarm sequences revealed that the swarms actually followed the slow earthquakes. The microearthquakes were a response to the stress perturbations caused near the slow earthquake.

Whereas nearly instantaneous movement on these faults has been responsible for damaging earthquakes (most recently in 1975 and 1989), flank movement is now also understood to occur in almost unnoticed slow jerks as it did earlier this week.

“Slow earthquakes,” which we have only just begun to study, appear to be a benign way to relieve volcano stress.

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

As Volcano Awareness Month nears its end, we conclude our look at volcanoes and society by exploring the cinematic treatment of volcanoes over the last century.

Given the infamy of the A.D. 79 eruption of Vesuvius, it is not surprising that the first volcano-related film was “The Last Days of Pompeii,” an 1897 silent film based on a novel that was first published in 1834. Several additional films with the same name have been made over the century since, with Hollywood first producing its own version of the story in 1935.

Sergio Leone (famous for directing Clint Eastwood in the now-classic spaghetti westerns) co-wrote and co-directed a version of the story in 1959. In 1984, the story was made into a TV mini-series that featured Laurence Olivier, Ernest Borgnine, and Ned Beatty.

Volcanoes, however, are rarely the focus of a movie (even if they dominate the title), and are used, instead, to provide a backdrop for human drama. In the 1950 film “Stromboli,” Ingrid Bergman plays the role of a woman from eastern Europe who escapes an internment camp by marrying an Italian and moving to his home on the volcanic island of Stromboli. There, she has to deal with not only eruptions from the volcano, but also with being an outsider.

The film is perhaps better known for the real-life drama of the affair between the actress and director Roberto Rossellini (both married to other people at the time), which led to a child born out of wedlock and the public condemnation of Bergman in the United States.

Volcanoes have also been featured in cartoons, including the animated Superman short “Volcano” from 1942 (viewable on the Internet through YouTube). In the cartoon, Superman saves Lois Lane from lava flows erupted by Monokoa volcano (perhaps a play on the name of Hawaii’s Mauna Loa volcano?), then diverts the lava to save a nearby town.

The late 1960s, 1970s, and early 1980s, saw the production of numerous disaster movies, featuring building fires, overturned ocean liners, and earthquakes. Volcanoes, of course, were also a primary backdrop for such movies. “Krakatoa, East of Java,” released in 1969, tells the story of a salvage boat captain who searches for sunken treasure with his mistress while he transports a shipload of convicts and tries to avoid a volcanic eruption.

The filmmakers must never have looked at a map of Indonesia, however, since Krakatau volcano (sometimes called Krakatoa) is located west of the island of Java.

The 1980 volcano disaster movie “When Time Ran Out” stars such Hollywood legends as Paul Newman, Jacqueline Bisset, and William Holden. The setting is a tropical island reminiscent of Hawaii, where an oil driller has to rescue tourists from the erupting volcano.

The movie was filmed on the Big Island, including scenes of Paul Newman walking across Kilauea Iki crater in his silver suit. While Newman reportedly regretted making the movie, he used his salary from the film to start the Newman’s Own company.

Movies featuring volcanoes have also been beautiful, as well as funny. Akira Kurosawa, the visionary filmmaker behind the classic film “Seven Samurai,” also directed the 1990 film “Dreams,” a collection of short stories based on Kurosawa’s own dreams. One dream involved a nuclear meltdown that led to an eruption of Mount Fuji (the film was co-produced by Steven Spielberg, with special effects by George Lucas).

Also in 1990, the movie-going public was treated to the now cult-comedy “Joe Versus the Volcano,” starring Tom Hanks and Meg Ryan. Who can forget a volcano named “The Big Woo”?

The late 1990s and 2000s saw an explosion of volcano movies, including 1997’s “Dante’s Peak” and 2005’s docudrama “Supervolcano.” Many of these films have been surprisingly realistic in terms of their portrayal of volcanic eruptions.

While the same cannot be said for 1997’s “Volcano” (about an eruption in Los Angeles, and starring Tommy Lee Jones and Ann Heche), at least many recent movies included professional volcanologists as advisors.

Perhaps this trend will continue, and we can look forward to future movies that have all the drama that viewers crave, while retaining realistic representations of volcanoes and their eruptions. Certainly an event as spectacular as a volcanic eruption needs no embellishment from Hollywood!

We hope you have enjoyed this series of articles on the interactions between volcanoes and religion, art, literature, and the movies, as well as other events associated with Volcano Awareness Month. Best wishes, and Happy 2010 from the staff of the Hawaiian Volcano Observatory!

(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.