August 15, 1997

A weekly feature provided by scientists at the Hawaiian Volcano Observatory.

Kilauea and Mars

One of the most highly watched events recently on television occurred on the Fourth of July when the U.S. Mars Pathfinder mission successfully transmitted images from the red planet back to Earth. The panorama of the Martian landing site had a striking semblance to the boulder-strewn field south of Halema`uma`u crater. This similarity probably did not surprise the planetary geologists, for they have long recognized that the closest earthly counterparts of Martian volcanic landforms are found in Hawaii.

In February 1995, a prototype Mars robotic vehicle, the Marsokhod Rover, was field-tested in the martian-like terrain south of Halema`uma`u. The vehicle was teleoperated by engineers who issued commands from the NASA Ames Research Center in California. The Kilauea tests provided invaluable information to NASA.

Whenever the Sojourner Rover encounters a problem on Mars, NASA simulates the situation, using a model to attain a solution. The red ash seen in the NASA model is from a Mauna Kea cinder cone off the Saddle Road. NASA believes that this ash has similar properties to the ash found on Mars.

Preliminary analyses by instruments on Sojourner indicate that the two rocks, Yogi and Barnacle Bill, are volcanic. Yogi is a basalt, like the lavas of Mauna Loa and Kilauea. Barnacle Bill is an andesite, a rock similar to basalt but containing less iron and more silica. This rock indicates that igneous activity on Mars may have been more complex than originally thought. Research conducted by USGS petrologists (geologists who study the composition, origin, occurrence, and structure of rocks) at HVO will help unravel the past volcanic processes of Mars.

This close relationship between NASA and the USGS at HVO is not new. Early in 1965, Neil Armstrong and 15 other astronauts spent two weeks at HVO learning about volcanic structures and rocks. These training sessions were repeated in 1967 and in 1969. One of the exercises was to drive a vehicle similar to the lunar buggy around a course in the Ka`u desert.

In the early '70s, photographs from the Mariner and Viking missions to Mars revealed the similarities between Martian and Hawaiian volcanic features. NASA researchers working with these images routinely spent part of their time in Hawai`i to improve their interpretation of the structures.

More recently, remote sensing instruments on NASA shuttles and satellites have been able to detect surface deformation, gas emissions, and temperature changes of our volcanoes. HVO provides ìground truthî or confirmation of these observations. Some day, through the efforts of NASA, USGS, and the University of Hawaii 's Space Grant Consortium, the volcanoes of the world will be monitored by our assets in the sky.

Kilauea Eruption Status--August 15, 1997

Kilauea's east rift zone eruptive activity continued during the past week with cyclic filling and lowering of the lava pond within Pu`u `O`o crater. Sporatic fountaining was observed from the crater cone and the 55 spatter cone vents. During the early morning hours of August 11, lava flowed into the Waha`ula heiau complex and completely inundated the structures. A corner of the Royal Gardens access road was covered by the same flow which entered the ocean near Waha`ula. Another lobe of the flow entered the ocean in the Kamokuna area, 900 meters to the west of Waha`ula. The public is reminded that the ocean entry areas are extremely hazardous, with explosions accompanying frequent collapses of the lava delta. The steam cloud is highly acidic and laced with glass particles.

Recent Big Island Earthquakes

Several earthquakes were felt during the past week. The largest was felt island-wide on Thursday afternoon at 3:54 p.m. and originated from the south flank of Kilauea. The temblor was located 7 km (4 mi) southwest of Pu`u `O`o at a depth of 5 km (3 mi.) and had a magnitude between 4.5 and 4.8. The epicenter is in the same general area as the magnitude 5.3 earthquake felt earlier this summer on June 30th. A resident of Pahala felt two earthquakes on Friday, August 8 at 11:03 a.m. and 3:24 p.m., respectively, and one on Sunday, August 10 at 7:39 p.m. The earthquakes were located 8 km (4.8 mi) northeast of Pahala at a depth of 6 km (3.6 mi). The first temblor had a magnitude of 3.3, the second had a magnitude of 2.7, and the third registered at 2.8.