Living with Hawaii's Active Volcano: Introduction

This is the first in a series of articles about living near Kilauea, Hawaii's most active volcano. Kilauea has entered a particularly vigorous eruptive phase that already is affecting the health and well-being of some nearby residents;it has the potential to disrupt thousands of lives in the near future.

I live on the Big Island of Hawaii, the southernmost and easternmost of all the Hawaiian islands. Geologically, the Big Island is comprised of five volcanoes melded together. The volcanoes dominate the landscape here. Historically they have determined or influenced everything from the island's various microclimates and weather, to the fertility of the island's soil.

I live on the western slope of one of those five volcanoes, Kohala, which is extinct. Another volcano on this island, Mauna Kea, last erupted thousands of years ago. It is considered to be 'dormant.' In other words, although it is quiet now, Mauna Kea is believed to be still capable of erupting again.

There are three active volcanoes on the island: Hualalai, Mauna Loa, and Kilauea. Hualalai last erupted more than 200 years ago, but geoscientists say that this volcano is likely to erupt again some time in the next 100 years. Mauna Loa has erupted 33 times since the mid-nineteenth century. It last erupted in 1984, and is monitored daily for signs that another eruption is about to commence.

That's Mauna Loa in the picture at right. I took the photo in January of 2006. You can see that it has some snow on its summit. Both Mauna Loa and Mauna Kea are snowcapped every winter, usually from some time in late November until some time in March.

Then there is Kilauea. Described by the U.S. Geological Survey (USGS) as "perhaps the world's most active volcano," Kilauea has been erupting continuously since January of 1983. The USGS also tells us that "it will surely continue to erupt through the rest of human history."

Lava oozes with little interruption from Kilauea's multiple vents, and flows for many miles down the slopes of the volcano to the ocean. Occasionally more dramatic events, called 'fountaining', cause jets of lava from fissures to shoot hundreds of feet into the air, a truly spectacular sight.

Kilauea is the centerpiece of the Hawaii Volcanoes National Park, and the park itself is considered a 'must see' for visitors to the Big Island. In addition to viewing areas from which visitors can see the current lava flows, the park has many hiking trails. One of those, called Devastation Trail, is pictured at left. The trail runs through an area that was a forest -- until it was devastated by falling cinder during a 1959 eruption from a vent known as Kilauea lki.

For those of us who live here, the volcanoes are much more than a tourist attraction -- especially Kilauea. This volcano currently is emitting more than lava, and it is those emissions that are most worrying to island residents.

Kilauea emits steam, ash, and a mixture of gases, some of which are potentially toxic. The volume of emissions, and the concentration of toxic gases has increased dramatically in recent weeks, a situation that has serious public health implications. Parts of Hawaii Volcanoes National Park have had to be closed to visitors, and high levels of sulfur dioxide and volcanic ash have been detected in the air of residential communities downwind of the eruption.

Kilauea's emissions are creating a health hazard in a much wider area as well. Although the situation in other communities still is less urgent than in areas directly downwind of the volcano, conditions could worsen with just a shift in wind direction, we are told.

In the next post, I will elaborate on the nature of the health risks from Kilauea's emissions, some of which I face myself, and I will explain why concern about the world's most active volcano is growing to new levels among Hawaii's residents.

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For more information about these volcanoes, visit the Hawaiian Volcanoes page on the Hawaiian Volcano Observatory website, run by the U.S. Geological Survey.