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What
are my risks?
Eruptions on Kauai
The
main mass of Kauai is about 3 to 5 million year old, although
there were a few very small eruptions on the island as
late as about 400,000 years ago! After a long period of
no eruptions (maybe something like 1/2 to 1 and 1/2 million
years, the latest stage of volcanism occurred on Kauai,
the post-erosional, or rejuvenated stage. On Kauai, the
lavas and other volcanic material from this stage have
been called the Koloa Volcanics.
Vog
and Laze Hazards for Kauai County
Although
the Koloa, Makaweli, and Napali volcanoes are probably
dead, volcanic hazards do affect the island. Volcanoes
spew noxious plumes of acidic gases. The resulting vog
and laze effect many communities across Kauai County.
When
a volcanic erupts, sulfur dioxide within the molten rock
is converted to sulfuric acid. The resulting plume is
known as vog (volcanic fog). Gases are also produced at
the ocean. When the lava enters the ocean, hydochloric
acid is produced - called laze (lava haze). Both of these
gases can contain particulate matter, such as volcanic
glass or trace metals.
Vog
and laze are carried by winds across the county. The impacts
include:
- obscured
views;
- lower agricultural
yields for certain crops;
- adverse
health effects for people with respiratory or heart
conditions; and
- acidified
rainwater catchment tanks (which, in turn, produces
a secondary hazard of leached lead in local water supplies).
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