Lava Zones on the Big Island

The cover story in this morning’s West Hawaii Today is about viewing the current activity at Halemaumau Crater in Hawaii Volcanoes National Park. Like many people, the presence of an active volcano was the reason I first visited the Big Island some thirty years ago.

Cinder cone on Mauna Loa, Hawaii

At that time Mauna Loa was erupting, and my partner and I made reservations with the Park Service to spend the night in cabins on a 3-day hike to the summit, where we could stay up late on a crystal clear night watching the glow and pops of molten lava in the crater below.

Although every visitor dreams of seeing a lava flow up close and personal, every prospective buyer of Big Island real estate hopes NOT to see lava flowing to their doorstep! Last week, I wrote about vog conditions resulting from the current eruption pattern, so it seems appropriate to tackle the more fundamental potential risks of living on an island with active volcanoes.

Although scientists studying the eruptions of Kilauea and Mauna Loa are learning more each day about the nature of volcanic activity, the predictive power of their theories is weak, both on the when and the where of a lava flow that could significantly affect inhabited areas. However, since most parts of the Big Island have not had lava flows for hundreds, thousands, or tens of thousands of years, the U.S. Geological Survey feels confident enough to map Lava Hazard Zones based upon the likelihood of areas receiving a near-term flow of lava. Lava Zone 1 is the most hazardous (a few areas on the flanks of the active volcanoes where most recent outbreaks have occurred) and Lava Zone 9 is the least hazardous (in North Kohala which is also the lowest vog zone).

Big Island Lava Flows Since 1800 (Atlas of Hawai’i (1999), Cartography
by Tom Paradise)

The orange squiggles in the map above show lava flows in the last 200 years or so. The lines around the middle on the left side of the map are all the lava you see in Kailua-Kona and driving up from the Kona airport to the Kohala Coast resorts. From a practical point of view, the Lava Zones are 3 and 4, which means that you will not have any premium on your insurance as the chances are negligible of you seeing a lava flow from your lanai.

You will also notice a heavy pattern of lines going to the center right of the map which is Hilo Bay, along the border between lava zones 2/3 and the sheltered zone 8. Notice that although the current eruption is at Kilauea, it is Mauna Loa, silent for 25 years, whose next eruption concerns scientists and should be of concern to homeowners in the zones considered most likely to be affected. If you own property in areas shown as Lava Hazard Zone 2 in Puna, Ka’u and South Kona districts, you will pay a higher homeowners insurance premium.

How much do Big Island residents worry day-to-day about the potential dangers of the next eruption? Certainly no more than California residents worry about living on the San Adreas fault. Definitely less than residents of the Gulf Coast worry about hurricanes. Even less than the typical Midwesterner or New England native thinks about blizzards and ice storms.

And neither earthquakes nor hurricanes nor snowstorms give Mainland residents a good reason to take a long weekend vacation. Whereas we might spend the night near Hawaii Volcanoes National Park, drive down to look for glow after dark, perhaps watch one of the many cultural programs or take a class at the Volcano Center for the Arts!

Additional Resources:

• Hawaii Volcanoes National Park Official Website
• Island of Hawaii Lava Hazard Zones Map
• Volcano Art Center