January 15, 2009
A weekly feature provided by scientists at the Hawaiian Volcano Observatory.
Volcanic and manmade pollution cause similar effects
What's white and wet and green all over? Hint: this is a household problem that Big Island residents on rainwater catchment share with the citizens of Sweden. Answer: a bathtub or wash basin coated with green copper sulfate.
For newcomers to the island, it may be reassuring to learn that the green stuff on your plumbing fixtures is a mineral, not a vegetable. The sulfuric acid in our rain leaches copper from pipes and combines with soap to form copper sulfate that adheres to tubs.
Most of us know that we can thank our active volcano for the acidic rain. The ongoing summit and east rift eruptions of Kilauea are emitting 2,000 to 3,000 tons of sulfur dioxide (SO2) into the atmosphere every day. SO2 and other volcanic gases interact with the atmosphere and sunlight to form sulfate particles and tiny droplets of sulfuric acid. This mixture is responsible for both acid rain and the haze we call vog.
But what about those green bathtubs in Sweden? By the 1970s, Scandinavians were also suffering from acid rain. With their high per-capita level of blondes, the Swedes were even reporting a problem with green hair. Unfortunately for them, the source of their pollution wasn't a captivating volcano, but rather the heavily industrialized areas of Germany and Britain, where SO2 is created by burning sulfur-contaminated coal.
The most severe consequences of exposure to SO2 occurred in London in 1952, when a temperature inversion capped the city for four days, trapping a "black fog" of polluted air close to the ground. Many people died on the streets, and, in the end, 4,000 deaths were attributed to the smog. The primary cause of death was inhalation of SO2 and particulates created by coal-fired power plants and home furnaces.
The U.S. Clean Air Act of 1970 and similar measures in Western Europe resulted in much cleaner cities. However, some of this improvement was achieved by building ever taller smoke stacks, which caused the emissions to be carried hundreds of miles downwind, where hitherto pristine areas were plagued with acid rain. Acidification of lakes and soil in the U.S. northeast and Canada killed fish, damaged forests, and leached toxic metals into water supplies.
In 1990, Congress mandated that coal-fired power plants had to cut their SO2 emissions in half by 2010. Many plants found that meeting the new standards was more easily and cheaply achieved than first assumed, by switching to low-sulfur coal from Wyoming's vast strip mines.
Too bad Kilauea can't switch to low-sulfur magma! Since the new vent opened at the summit in March, SO2 emissions have increased by about 50 percent and vog impacts, especially to communities close to the source, have become even more serious. In addition to creating hazardous situations for people with respiratory ailments, farmers have suffered significant losses, prompting a disaster declaration from the USDA. A recent publication from the University Agricultural Extension Service, http://www.ctahr.hawaii.edu/oc/freepubs/pdf/PD-47.pdf, provides farmers with information on how to apply for relief funding. It is also useful for the home gardener, as it lists varieties of plants known to be susceptible to vog and has suggestions for helping to protect vulnerable plants. For more information, visit our Frequently Asked Questions list online at http://hvo.wr.usgs.gov/hazards/FAQ_SO2-Vog-Ash/main.html. Hawai`i County has advisories and a mitigation brochure on their website at http://www.lavainfo.us/. The State of Hawai`i also has online information at http://hawaii.gov/gov/vog.
Kīlauea Volcano continues to be active. A vent in Halema`uma`u Crater is emitting elevated amounts of sulfur dioxide gas but producing no ash. Resulting high concentrations of sulfur dioxide in downwind air have closed the south part of Kīlauea caldera and produced occasional air quality alerts in more distant areas, such as Pahala and communities adjacent to Hawai`i Volcanoes National Park, during kona wind periods.
Pu`u `Ō`ō continues to produce sulfur dioxide at even higher rates than the vent in Halema`uma`u Crater. Trade winds tend to pool these emissions along the West Hawai`i coast, while Kona winds blow these emissions into communities to the north, such as Mountain View, Volcano, and Hilo.
Lava erupting from the Thanksgiving Eve Breakout (TEB) vent at the eastern base of Pu`u `Ō `ō continues to flow to the ocean at Waikupanaha through a well-established lava tube. Breakouts from a western branch of the lava tube were active on the coastal plain near the National Park boundary in the past week. As of Thursday, January 15, these flows were within a few hundred yards of the ocean. Long-lived ocean entry activity at Waikupanaha has continued throughout the past week, with no reported fluctuations following a brief deflation-inflation cycle on January 12.
Be aware that active lava deltas can collapse at any time, potentially generating large explosions. This may be especially true during times of rapidly changing lava supply conditions. The Waikupanaha delta has collapsed many times over the last several months, with three of the collapses resulting in rock blasts that tossed television-sized rocks up onto the sea-cliff and threw fist-sized rocks more than 200 yards inland.
Do not approach the ocean entry or venture onto the lava deltas. Even the intervening beaches are susceptible to large waves generated during delta collapse; avoid these beaches. In addition, steam plumes rising from ocean entries are highly acidic and laced with glass particles. Call Hawai`i County Civil Defense at 961-8093 for viewing hours.
Mauna Loa is not erupting. Four earthquakes were located beneath the summit this past week. Continuing extension between locations spanning the summit indicates slow inflation of the volcano, combined with slow eastward slippage of its east flank.
No earthquakes beneath Hawai`i Island were reported felt within the past week.
Visit our Web site (http://hvo.wr.usgs.gov) for daily Kīlauea eruption updates, a summary of volcanic events over the past year, and nearly real-time Hawai`i earthquake information. Kīlauea daily update summaries are also available by phone at (808) 967-8862. Questions can be emailed to askHVO@usgs.gov.
Updated: January 20, 2009 (pnf)