January 16, 2003
A weekly feature provided by scientists at the Hawaiian Volcano Observatory.
Mahalo for Helping Us Celebrate Pu`u `O`o's 20th Anniversary
On January 4, as lava flowed from the Pu`u `O`o cone 11 km (7 miles) to the south shoreline of Kilauea Volcano, the staff of the Hawaiian Volcano Observatory welcomed the public to our Open House in the Park, celebrating the twentieth anniversary of the eruption.
We thank all who visited the Park and showed a keen interest in our work and in exposing children to earth and life sciences. We also thank the staff of Hawai`i Volcanoes National Park, USGS Kilauea Field Station, University of Hawai`i Hilo, Kilauea Military Camp, Volcano House, and the Volcano Art Center who gave their time and energy to make this a truly special event.
The Open House gave us the opportunity to demonstrate how we monitor Hawai`i's volcanoes and describe new ideas learned from studying the geology of the Big Island, tracking changes that precede and accompany eruptions, and conducting surveys of active lava tubes.
For those who wanted to know "what the volcanoes are doing right now," we showed our monitoring data in real time using new computer programs. Developed only in the past year, a program called VALVE (Volcano Analysis and Visualization Environment) enables us to analyze real-time and archived data from our various instruments, measurements, and surveys, and model the data to identify possible explanations for what was observed.
We also demonstrated Earthworm, a new computer program that enables us to digitally record, locate, determine magnitude, and analyze earthquakes in Hawai`i. This digital version, compared to the paper drum record, allows any ground-shaking signal to be magnified in remarkable detail, and to be displayed and analyzed in a variety of ways.
We showed two different methods for determining possible pathways of future lava flows during the initial onset of a hypothetical eruption on Kilauea and Mauna Loa volcanoes. A set of soon-to-be-released maps identifies broad areas that can be covered by lava erupted from future vents on Mauna Loa's northeast and southwest rift zones. The inundation zones are based on the volcano's history of lava flows. More specific pathways of future lava flows that spread over new ground can be accurately determined based on the topography of the Big Island.
Back in our mineralogy lab, children and their parents enjoyed looking at different types of volcanic products, as well as thin sections of rocks through a microscope that allow different kinds of minerals to be seen. In our gas lab, visitors were shown how we analyze and measure volcanic gases released from Kilauea, and they had the pH of their drinking water tested.
Outdoors in the Park, HVO scientists showed visitors evidence of explosive eruptions at Kilauea in 1924 and much larger explosions that occurred many times in the past 1,200 years. Oral history describes some of these explosions, which enhanced Pele's reputation for her terrible temper.
We also demonstrated how geophysical surveys are conducted over active lava tubes to determine the size and shape of the underground tube. When we can also estimate the speed of the lava stream within an active tube, for example through a skylight, we can calculate the discharge of lava through a tube system. These data enable us to determine how much lava Kilauea erupts every day and study the evolution of lava flows over time.
The popular Pu`u `O`o drawing contest brought many children from all over the world to depict their views of the ongoing eruption. Winners of the drawing contest are as follows: first prize, : Riker Kasamoto (age 7, Honolulu), for his drawing of Pu`u `O`o with a lava fountain, whose flow went underground through a lava tube, then poured into the ocean at the coast. Second prize went to Miki Karpik (age 11, Pahoa), who depicted the sea goddess Namakaokahai welcoming the tempestuous Pele, emerging from Pu`u`O`o, to come to her domain. Sarah Miller (age 8, no address given), showed Pele with her tears, rising from the lava fountain of Pu`u `O`o, with a girl running toward her home, endangered by the flowing lava. We congratulate all of the young artists for their creativity and imagination.
Eruptive activity at the Pu`u `O`o vent of Kilauea Volcano continued unabated during the past week. Lava flows through a tube system from the vent to the sea. Lava continues to enter the ocean and form lava deltas (benches). Only the West Highcastle delta stayed active for the entire week; the Highcastle and Wilipe`a deltas both shut down last week. A substantial new flow tongue, visible on Pulama Pali last week, developed two branches that made it over Paliuli and are now spreading slowly across the coastal flat.
The West Highcastle lava delta has had several small collapses in the past week, and explosions have been common. The public should be aware that the ocean entry areas can collapse at any time, potentially generating large explosions in the process. The steam clouds rising from the entry areas are highly acidic and laced with glass particles. The National Park Service has erected a rope barricade to delineate the edge of the restricted area. Do not venture beyond this rope boundary onto the lava deltas and benches. Even the intervening beaches are susceptible to large waves suddenly generated during delta collapse; these beaches should be avoided.
Four earthquakes were reported felt on the island during the past week. A resident of Kealia felt an earthquake at 8:29 a.m. on January 12. The magnitude-2.4 earthquake was located 2 km (1.2 mi) west of Pahala at a depth of 36.4 km (21.8 mi). A camper in Hawai`i Volcanoes National Park was awaken by an earthquake at 4:37 a.m. on January 13. The magnitude-3.2 temblor was located 13.3 km (8 mi) beneath Lo`ihi Volcano. Later the same day at 5:12 p.m., residents of Puna were shaken by a magnitude-2.8 earthquake located 8 km (5 mi) east of Pu`ulena Crater at a depth of 4 km (2.4 mi). Another earthquake on January 13 at 5:55 p.m. was felt by residents of Hilo and Papa`ikou. The magnitude-2.9 shaker was located 6 km (3.6 mi) southeast of Pu`u `O`o at a depth of 8.6 km (5.2 mi).
Mauna Loa is not erupting. The summit region continues to inflate, though the rate of inflation has slowed gradually during the past month or two. The earthquake activity is low, with only 1 earthquake located in the summit area during the last seven days.
Updated: January 23, 2003 (pnf)