Unified Interior Regions

By anyone's reckoning, New Year's Day either starts a new millennium or ends its first year. What have Hawai`i's four active island volcanoes done during the past 1,000 years?
 

For the past two weeks, numerous reports of increased seismic activity heralding a possible large eruption at Popocatepetl Volcano in Mexico have been in the news. A disturbing commentary in the reports was that residents living on the slopes of the volcano were hesitant to comply with the government's order to evacuate.
 

It's been 60 years since Harold Stearns first recognized that Hawaiian island volcanoes evolve through stages we call shield, postshield, and rejuvenated volcanism.

Two months ago, we discussed early findings suggesting that Kīlauea had an explosive eruption far larger than we dared think. The study has progressed since then, and the early findings have been confirmed and extended.
 

Last week we wrote about the large Kalapana earthquake of 1975. In the article we discussed the importance of repeated geodetic observations that monitored the accumulation of strain before the earthquake and allowed HVO researchers to forecast the event.

Wednesday, November 29, 2000, will mark the 25th anniversary of the magnitude 7.2 Kalapana earthquake that struck the Puna and Ka'u districts of Hawai'i County. The 1975 earthquake is the second largest ever documented in Hawai'i, overshadowed only by the 1868 great Ka'u earthquake, which has been estimated to be of magnitude 7.9.
 

The Kalij Pheasant is an unparalleled success among game birds introduced in the 50th State. Because Hawai`i has no native upland game birds, people have imported a total of twelve species of pheasants, quail, partridges, peafowl, and wild turkeys from all over the world. Last to arrive was the Kalij, released in 1962 at Pu`u Wa`awa`a Ranch.

Anyone who has been close to an active flow or steam vent knows that the heat coming from one of these features is intense and, at times, overwhelming! It will come as no surprise, then, that thermal monitoring of volcanoes and their products plays an important part in volcanology.
 

Kīlauea has been erupting for nearly 18 years, and there is no sign of it stopping anytime soon. But all previous Kīlauea eruptions ended, and there's no reason to think this one is any different. What can we expect when the curtain finally falls?
 

To many of us, Hawaiian volcanoes loom sleepily overhead, occasionally stirring from their slumber and oozing lava flows down their flanks toward the sea. Deep within the towering volcanoes, however, lies the potential for powerful explosions of volcanic ash and blocks.
 

Driving along the Queen Ka`ahumanu highway from Kailua-Kona to Waikoloa, one passes a vast expanse of well-exposed lava rock. These flows are from Hualālai and Mauna Loa Volcanoes and are of various ages. If you slow down and look carefully, you are able to recognize individual flows by their distinctive surface texture, color, or luster.