The Ka Lua o Lapa eruption

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The Ka Lua o Lapa eruption
Cape Kinau
La Pérouse Bay
By John Sinton, GG
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The only eruption on Maui for which there exist
historical accounts is the one from Ka Lua o
Lapa. These accounts were collected by Lorrin A.
Thurston and published in the Honolulu Advertiser
in 1924
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I asked the natives if they knew when that flow
occurred, and they told me that their
grandparents saw it. They also told me that a
woman and child were surrounded by the flow, but
escaped after it cooled. - account of Father
Bailey, told to J. D. Dana about 1841
Thurston reasoned that the eruption must have
occurred 99 years prior to 1841, or about 1742
A.D., assuming 33 years for the length of a
generation and an age of 33 years for the
natives who told the story.
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In 1906, Thurston was camped on Haleakala when he
encountered a cowboy named Charlie Ako. Ako told
Thurston I married a woman from Honuaula, and
my father-in-law, of Honuaula, who died last
year, at the age of 92 years, told me that when
the flow at Keoneoio ran out, his grandfather
saw it, and that, at that time, he (the
grandfather) said he was old enough to carry two
coconuts from the sea to the upper road.
From this, Thurston reasoned that the eruption
occurred about 1757 A.D. Akos father-in-law was
92 in 1905, and hence was born in 1813. His
father, perhaps born 33 years earlier in 1780,
was the father of the boy who carried the
coconuts. A boy old enough to carry coconuts
from the sea to the upper road must have been
at least 10 years old at that time.
Keoneoio
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Stearns and Macdonald (1942) questioned
Thurstons use of 33 years as the length of a
generation for Hawaiians of the time, and
suggested that 23 years might be a better
approximation. A shorter generation length makes
the flow even younger, perhaps around 1770
instead of 1750.
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Oostdam (1965) compared maps made by early
western explorers to look for possible changes in
the shoreline
Oostdam concluded that the flow that makes Cape
Kinau must have been erupted in 1790 3 A.D.
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1792
1786
Map drawn by Bernizet from the expedition of the
La Boussole and LAstrolabe under the command of
Captain Jean François de Galaup Comte de La
Pérouse
Map drawn by Joseph Baker from the cruise led by
Captain George Vancouver
Cape Kinau seems clearly to have been present in
1792. Whether or not it existed in 1786 is hard
to tell.
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Geologic Map of Honuaula
14C ages for selected lavas hkol 390 50 460
50 hkan 910 40 950 40 hhan 820 170 920
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Charcoal dating (consistent with paleomagnetic
pole determinations) suggest emplacement of Ka
Lua o Lapa lava in the period 1425-1613 A.D.
(about 500 yrs ago) From oldest to youngest,
Pimoe, Hanamanioa, and Kanaloa lavas were all
erupted about 800-1000 yrs ago.
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pau