REMAINS OF A CLAW from an extinct land crab has revealed important data on the age of a lava flow that covers much of Hawaiian Ranchos, a makai subdivision in Ocean View. The subdivision lies on two lava flow units. The older one, called Qk2 on Hawaiian geological maps, is thought to be from an eruption about 1,500 to 3,000 years ago. The newer one that thinly covers about a third of Qk2, called Qk3, is composed of `a`a lava thought to be about 750 to 1,500 years old.
Ranchos resident Ann Bosted said all known lava tubes in Ranchos are in the older flow. The younger flow contains lava caves, like the well-known Kula Kai Caverns, but they occur outside the subdivision where the flowing lava was deeper. Kula Kai is part of the Kipuka Kanohina system, which includes many caves in Hawaiian Ocean View Estates.Steve Smith, at left, and Professor Stephan Kempe examine a crab claw. Photo by Peter & Ann Bosted |
Bosted explained that lava caves form in pahoehoe flows. Once molten lava is contained in the lava tubes (also known as pyroducts), it stays extremely hot and therefore liquid, so that it can flow for many miles without stalling, until it reaches the oceanfront. “Once the lava stops flowing, many of the lava tubes remain intact as larger or smaller caves and can become subterranean shelters for creatures as diverse as insects, crabs, birds and goats,” Bosted said. “If animals die underground, their remains are well protected from scavengers and weathering and can lie undisturbed for many thousands of years. Thus, lava tubes can preserve clues to our past, including evidence that three species of land crabs once roamed the Hawaiian Islands in large numbers. They probably became extinct when humans arrived.”
Dr. Stephan Kempe, a recently retired professor of geology in Germany, regularly visits Hawai`i and is now one of the world’s foremost authorities on pyroducts. He recently visited a Ranchos lava tube in the Qk2 flow where he spotted a number of claws from the extinct land crab. With permission from the cave’s guardian, Steve Smith, he collected a sample claw and took it back to Germany for dating.
“The results blew me away,” Smith said. “Professor Kempe established its age to be 2,400 years with only about 30 years as the possible variation. I had no idea that anything could last that long in a lava tube.”
To Kempe, the geological significance is as important. “The Qk2 flow was thought to be 1,500 to 3,000 years old,” he said. “But we know you can’t have a crab claw that is 2,400 years old in a pyroduct that is 1,500 years old. It’s not possible. This claw means that the age of the flow can now be confidently set as 2,400 to 3,000 years old, an improvement on 1,500 to 3,000 years.”
“It is difficult for a geologist doing field work to establish the ages of flows. The best way is to find some organic material, like the remains of trees that were burned and buried by the lava when it flowed, and date them. Sometimes one can find bits sticking out from under the flow along its edges. This is hard to do, but that is how USGS geologists like Jack Lockwood and Frank Trusdale have established the ages of the flows, as depicted on current geological maps of Hawai`i.
“Finding a crab claw in the cave, while it does not indicate the flow’s exact age, can, in this case, at least establish the minimum age of the flow. If we were to find a claw that was older than 3,000 years, we would have to adjust the maximum age of the flow, too.”
How can one date an old crab claw with such accuracy? Kempe explained: “Crab claws, burnt trees or any other organic remains contain minute amounts of the radioactive carbon isotope No. 14, which decays with a half-life of 5,730 years. Thus, it can be used to obtain dates for the last few 10,000 years and is the isotope of choice for most archeological studies.
“The data we got for the crab claw was carefully compared with data that has been gathered from tree rings all over the world. Tree rings are so well documented that we can date individual years up to 10,000 years back. The results of carbon 14 dating are reported in radiocarbon years and, ‘calibration’ is needed to convert radiocarbon years into calendar years. The date for this crab claw happens to fall on a good period and is therefore relatively exact.
How can one date an old crab claw with such accuracy? Kempe explained: “Crab claws, burnt trees or any other organic remains contain minute amounts of the radioactive carbon isotope No. 14, which decays with a half-life of 5,730 years. Thus, it can be used to obtain dates for the last few 10,000 years and is the isotope of choice for most archeological studies.
“The data we got for the crab claw was carefully compared with data that has been gathered from tree rings all over the world. Tree rings are so well documented that we can date individual years up to 10,000 years back. The results of carbon 14 dating are reported in radiocarbon years and, ‘calibration’ is needed to convert radiocarbon years into calendar years. The date for this crab claw happens to fall on a good period and is therefore relatively exact.
“If more money were available for this sort of study, we could more accurately date the individual lava flows, but each carbon dating costs at least $300. We may need to make 10 or 20 or 30 tests, so the costs can add up fast.”
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Maile David |
HAWAI`I COUNTY COUNCIL last week approved resolutions to support upcoming programs in Ka`u. Ka`u’s Council member Maile David introduced the resolutions.
Res. 430-16 provides $5,500 to support TropiCare 2016 at Ocean View Community Center from May 30 to June 4. The training program by the U.S. Department of Defense brings military reservists to Ka`u to provide free medical care to the public. The program is an exercise of the Innovative Readiness Training Program, which challenges reservists to plan and implement rapid mobilizations to distant and unfamiliar areas.
Ocean View resident Richard Abbett testified in support of the resolution. “We not only are underserved; we rarely are served in Ka`u,” he said.
Other resolutions fund up to 60 scholarships for Summer Fun programs in Pahala, Na`alehu and Ocean View. Each location will receive $2,000 to keep up to 20 keiki busy when school is out of session.
Another resolution appropriates $5,000 for repairs at Ocean View Fire Station, including to its 3,000-gallon water tank.
Abbett said he appreciates support for fire station repairs in advance of more funding that he hopes may be provided through the next county budget for equipment.
Ocean View resident Tony Columbo is a volunteer firefighter there. He said funds would go toward normal upkeep at the fire station. He asked David to remain “aggressive” in supporting the community.
David will be at Ocean View Community a week from today on Monday, March 28 at 6 p.m. to answer questions about local issues.
To read comments, add your own and like this story, see facebook.com/kaucalendar.
Ocean View resident Richard Abbett testified in support of the resolution. “We not only are underserved; we rarely are served in Ka`u,” he said.
Other resolutions fund up to 60 scholarships for Summer Fun programs in Pahala, Na`alehu and Ocean View. Each location will receive $2,000 to keep up to 20 keiki busy when school is out of session.
Another resolution appropriates $5,000 for repairs at Ocean View Fire Station, including to its 3,000-gallon water tank.
Abbett said he appreciates support for fire station repairs in advance of more funding that he hopes may be provided through the next county budget for equipment.
Ocean View resident Tony Columbo is a volunteer firefighter there. He said funds would go toward normal upkeep at the fire station. He asked David to remain “aggressive” in supporting the community.
David will be at Ocean View Community a week from today on Monday, March 28 at 6 p.m. to answer questions about local issues.
To read comments, add your own and like this story, see facebook.com/kaucalendar.
Dr. Virginia Pressler |
HAWAI`I DEPARTMENT OF HEALTH is investigating its second imported case of Zika virus to be confirmed this year by the department’s State Laboratories Division. The Kaua`i resident has a history of recent travel to Latin America and may still be infectious. The individual has been advised to keep indoors and stay protected from mosquitoes.
A Vector Control team will visit the individual’s residence to survey the area for mosquitoes and determine if there is a need to treat the area to reduce any mosquito breeding sites.
“As Zika continues to spread in multiple regions across the world, we anticipate that we will experience an increase in imported cases and must take precautionary measures to reduce our risk for an outbreak in Hawai`i,” DOH Director Dr. Virginia Pressler said. “It is crucial that we keep practices (such as eliminating standing water and wearing mosquito repellent) top-of-mind as we prepare for travel in and out of the state, especially to areas that may be affected by Zika and other mosquito-borne illnesses.”
For more information on Zika, see cdc.gov.
“As Zika continues to spread in multiple regions across the world, we anticipate that we will experience an increase in imported cases and must take precautionary measures to reduce our risk for an outbreak in Hawai`i,” DOH Director Dr. Virginia Pressler said. “It is crucial that we keep practices (such as eliminating standing water and wearing mosquito repellent) top-of-mind as we prepare for travel in and out of the state, especially to areas that may be affected by Zika and other mosquito-borne illnesses.”
For more information on Zika, see cdc.gov.
MILOLI`I-KA`U GIRLS TRAVELING Volleyball Club has been invited to participate in the 29th annual Ho`oikaika Invitational Tournament May 27-30 on Kaua`i. Members have participated in various tournaments, including the annual Haili Tournament of Hilo, where they placed first and third in different divisions.
The club is raising funds to offset travel expenses that include flights, room and board and ground transportation.
“This will be our first off-island trip and an opportunity to compete with girls in our brackets from various neighboring islands, as well as an opportunity to expand our skills and abilities,” donations chair Starlette Freitas said. “Any contribution will be greatly appreciated.”
Players include Kyia Hashimoto, Hailey Fa`afia, Shaila Fa`afia, Honey Freitas, Lehiwa Freitas-Moses, Precious Mareko-Ke, Kaelyn Medeiros-Shibuya, Chelsea Velez, Johnette Llanes and Jaydah Pilanca-Emmsley.
Checks made payable to Starlette Freitas may be sent to her at PO Box 847, Na`alehu, HI 96772 with MK Volleyball Club noted on the check.
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“This will be our first off-island trip and an opportunity to compete with girls in our brackets from various neighboring islands, as well as an opportunity to expand our skills and abilities,” donations chair Starlette Freitas said. “Any contribution will be greatly appreciated.”
Players include Kyia Hashimoto, Hailey Fa`afia, Shaila Fa`afia, Honey Freitas, Lehiwa Freitas-Moses, Precious Mareko-Ke, Kaelyn Medeiros-Shibuya, Chelsea Velez, Johnette Llanes and Jaydah Pilanca-Emmsley.
Checks made payable to Starlette Freitas may be sent to her at PO Box 847, Na`alehu, HI 96772 with MK Volleyball Club noted on the check.
To read comments, add your own and like this story, see facebook.com/kaucalendar.
After Dark in the Park focuses on nene and `ua`u recovery efforts. Photo from NPS |
WILDLIFE BIOLOGIST KATHLEEN MISAJON highlights two critically endangered bird species, the iconic nene (Hawaiian goose) and the mysterious `ua`u (Hawaiian petrel), tomorrow at 7 p.m. at Kilauea Visitor Center Auditorium in Hawai`i Volcanoes National Park. Attendees learn about the park’s current and future monitoring programs and how these species are faring in the park and throughout Hawai`i.
$2 donations support After Dark in the Park programs; park entrance fees apply.
PARK RANGERS AND STAFF from Hawai`i Pacific Parks Association demonstrate various Hawaiian games Wednesday between 10 a.m. and 12 p.m. on Kilauea Visitor Center lanai in Hawai`i Volcanoes National Park. Free; park entrance fees apply.
Blacksmithing is the topic Wednesday at Na`alehu Public Library. |
NA`ALEHU PUBLIC LIBRARY hosts a free, live Blacksmithing Demonstration on Wednesday at 2 p.m. Journeyman blacksmith Richard Blaine, assistant Schaunlee Blaine, apprentice Ian Bailey and knifemaker David Brunetta practice the time-honored craft and tell a bit about its history.
All ages are welcome; young children must be accompanied by an adult.
Call 939-2442 for more information.
SUPPORT OUR SPONSORS AT PAHALAPLANTATIONCOTTAGES.COM AND KAUCOFFEEMILL.COM. KA`U COFFEE MILL IS OPEN SEVEN DAYS A WEEK.
See kaucalendar.com/KauCalendar_March_2016.pdf. |
See kaucalendar.com/TheDirectory2016.pdf. |