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| Happy Labor Day! According to Hawaiian Volcano Observatory scientists, "charcoal is good for more than the barbeque." See below. Photo from Wikipedia |
SHOULD HAWAI`I ERADICATE MOSQUITOES? A group of stakeholders will ponder the question during meetings this week at Kilauea Military Camp in Hawai`i Volcanoes National Park.
“We are discussing sort of how we realize the potential for a mosquito-free environment here for public health, conservation and quality of life issues,” Durrell Kapan, co-organizer of the workshop and adjunct professor at the Center for Conservation and Research Training at UH-Manoa, told Max Dible, of West Hawai`i Today. |
| Dr. Kenneth Kaneshiro |
“There are a number of near-term and potentially longer-term solutions. The important thing is to make sure all the people involved are thinking about these solutions, and to get all those people in the room to understand what those possibilities are.”
Dr. Kenneth Kaneshiro, program director at UH-Manoa’s Center for Conservation and Research Training, explained that mosquitoes could be controlled by interrupting the insects’ reproductive systems.
When Dible asked about consequences of eradication, such as reducing food supplies for species such as hoary bats, Kaneshiro said, “Eradication of mosquitoes wouldn’t cause any other problems because they’re not native to Hawai`i. They’re an invasive species that doesn’t belong in the native Hawaiian ecosystem.” He said the ecosystem worked fine before mosquitoes were introduced.
See westhawaiitoday.com.
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When Dible asked about consequences of eradication, such as reducing food supplies for species such as hoary bats, Kaneshiro said, “Eradication of mosquitoes wouldn’t cause any other problems because they’re not native to Hawai`i. They’re an invasive species that doesn’t belong in the native Hawaiian ecosystem.” He said the ecosystem worked fine before mosquitoes were introduced.
See westhawaiitoday.com.
To read comments, add your own, and like this story, see Facebook. Follow us on Instagram and Twitter.
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| Sen. Brian Schatz |
KA`U’S U.S. SENATORS send Labor Day greetings to their constituents.
“On Labor Day, we honor the work and sacrifice of the labor movement in our country,” Sen. Brian Schatz said. “We thank labor unions as champions for the minimum wage, Social Security, workplace health and safety standards, child labor protections and the 40-hour work week, but our thanks must be more than just words.
“As Congress returns to session this week, we must focus on the fact that millions of working families are struggling to make ends meet. We are the wealthiest country in the world and yet for far too many Americans, a full-time job still means a life below the poverty line. We must do better. I look forward to working with my Senate colleagues to make real progress toward improving the lives of working families in our country.”
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| Sen. Mazie Hirono |
Sen. Mazie Hirono said, “When my mother brought our family to Hawai`i, we struggled. We lived in fear of mom getting sick and not being able to work – which meant no pay and no money for food or rent. She had no employment protection. But our family circumstances changed dramatically when mom’s workplace unionized. Better job security, better pay. We were finally able to buy our first home. As we celebrate LaborDay, we celebrate the men and women who fought and sacrificed for basic protections, like safe working conditions and fair wages, that American workers have today.”
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AS KA`U RESIDENTS ENJOY Labor Day barbeques, Hawaiian Volcano Observatory geologists explain in the current issue of Volcano Watch how they use charcoal.
“One of the fundamental premises of geology is that the key to understanding the future is to look at the past,” the article states. “In order to understand how a volcano will behave, geologists map the deposits of past eruptions.
“One of the fundamental premises of geology is that the key to understanding the future is to look at the past,” the article states. “In order to understand how a volcano will behave, geologists map the deposits of past eruptions.
“An important element for characterizing volcanic deposits is to establish if the eruption was predominantly effusive (characterized by lava flows) or explosive. Furthermore, we want to know the spatial distribution of the deposits, and how frequently and where the different types of eruptions occur.
“To help determine the timing of eruptive activity, geologists use a radiocarbon age-dating technique. Collecting charcoal is the most common method used in Hawai`i, not only by geologists, but also by archaeologists, ecologists, and others.
“How does radiocarbon, or carbon-14, dating work?
“Carbon-14 is produced in the atmosphere and readily utilized by plants to build tissue, fiber, and wood. Carbon-14 is radioactive and has a half-life of 5,700 years. As long as a plant is alive, the amount of carbon-14 in its tissue remains approximately the same.
“Once the plant dies, however, the quantity of carbon-14 in the plant tissue decays, so that after 5,700 years the amount of carbon-14 is 50 percent of the amount present when the plant was alive. After another 5,700 years, the concentration is down to 25 percent of its initial concentration.
“Any high temperature volcanic product, such as a lava flow, spatter, and hot ash, can create charcoal when it burns or buries a plant. In Hawai`i, geologists dig under lava flows to recover charcoal left from plants.
“To help determine the timing of eruptive activity, geologists use a radiocarbon age-dating technique. Collecting charcoal is the most common method used in Hawai`i, not only by geologists, but also by archaeologists, ecologists, and others.
“How does radiocarbon, or carbon-14, dating work?
“Carbon-14 is produced in the atmosphere and readily utilized by plants to build tissue, fiber, and wood. Carbon-14 is radioactive and has a half-life of 5,700 years. As long as a plant is alive, the amount of carbon-14 in its tissue remains approximately the same.
“Once the plant dies, however, the quantity of carbon-14 in the plant tissue decays, so that after 5,700 years the amount of carbon-14 is 50 percent of the amount present when the plant was alive. After another 5,700 years, the concentration is down to 25 percent of its initial concentration.
“Any high temperature volcanic product, such as a lava flow, spatter, and hot ash, can create charcoal when it burns or buries a plant. In Hawai`i, geologists dig under lava flows to recover charcoal left from plants.
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Dark-colored charcoal, left of rock hammer, from a log buried by lava
was found at the base of an `a`a flow in Ka`u. Photo from USGS-HVO
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“Scientists use the decay rate of carbon-14 to obtain age-dates from this charcoal. A relatively new accelerator mass spectrometer technique can now provide ages between 80 and 100,000 years.
“Geologists often make assumptions about the charcoal they collect. We assume that plants are alive at the time an eruption occurs. In addition, we assume that charcoal is created when a lava flow covers the vegetation.
“These assumptions can create problems if the charcoal is created from wood that was already dead when it burned. There are other potential sources for confounding a radiocarbon age, such as dating forest fire charcoal or ‘old’ living wood, for example, the core of a log one meter (three feet) in diameter that could be quite a bit older than the exterior of the log.
“To minimize these problems, geologists make sure that collection techniques are impeccable to reduce the chance that spurious charcoal is recovered. We also try to minimize infiltration of contaminant charcoal. Given the choice of age-dating a log or a twig, we choose the twig to avoid inadvertently dating old wood in the interior of the log.
“Once charcoal is recovered, we dry the sample and pick out small pieces of black shiny charcoal that has a distinctive ‘snap’ when broken. Soft pliable charcoal is discarded. The sample is then sent to a radiocarbon-processing lab, where it is chemically treated to remove modern carbon. The sample is converted to graphite, which is used to determine the radiocarbon age.
“Once we get the results from the lab, how do we then decide if the age is ‘good?’
“The radiocarbon age has to fit into the stratigraphic framework based on geologic mapping of the volcanic deposit. For example, if Flow B, dated at 550 years old, is bracketed by Flow A, dated at 1,000 years, and Flow C, dated at 1,500 years, it is highly likely that the radiocarbon age of Flow B is not good, because it should be between 1,000 and 1,500 years.
“Once we determine that the radiocarbon results are consistent with stratigraphy, we have to calibrate the age. Calibration is necessary because, using tree-ring data from around the world, we know that the concentration of atmospheric carbon-14 varied from time to time, and we must account for this variability.
“Most ages are reported in years before present, with zero being A.D. 1950, before atmospheric atomic bomb testing altered the amount of carbon-14 in the air. If the age control is good enough based on stratigraphy, radiocarbon ages can be presented in terms of calendar years to facilitate comparison with non-geologic historical events.
“So, in geology (and other fields), charcoal can be useful for more than just grilling on the barbeque.”
See hvo.wr.usgs.gov/volcanowatch.
To read comments, add your own, and like this story, see Facebook. Follow us on Instagram and Twitter.
HAWAI`I COUNTY COUNCIL HOLDS its regular and committee meetings Wednesday. Full council meets at 9 a.m. Public Safety & Mass Transit Committee meets at 1 p.m.; Finance, 1:15 p.m.; Planning, 1:30 p.m.; Public Works & Parks & Recreation, 2 p.m.; and Governmental Relations & Economic Development, 2:45 p.m.
All meetings take place at Council Chambers in Hilo. Agendas and live-streaming are available at hawaii.county.gov.
Ka`u residents can participate via teleconferencing at Na`alehu State Office Building.
“These assumptions can create problems if the charcoal is created from wood that was already dead when it burned. There are other potential sources for confounding a radiocarbon age, such as dating forest fire charcoal or ‘old’ living wood, for example, the core of a log one meter (three feet) in diameter that could be quite a bit older than the exterior of the log.
“To minimize these problems, geologists make sure that collection techniques are impeccable to reduce the chance that spurious charcoal is recovered. We also try to minimize infiltration of contaminant charcoal. Given the choice of age-dating a log or a twig, we choose the twig to avoid inadvertently dating old wood in the interior of the log.
“Once charcoal is recovered, we dry the sample and pick out small pieces of black shiny charcoal that has a distinctive ‘snap’ when broken. Soft pliable charcoal is discarded. The sample is then sent to a radiocarbon-processing lab, where it is chemically treated to remove modern carbon. The sample is converted to graphite, which is used to determine the radiocarbon age.
“Once we get the results from the lab, how do we then decide if the age is ‘good?’
“The radiocarbon age has to fit into the stratigraphic framework based on geologic mapping of the volcanic deposit. For example, if Flow B, dated at 550 years old, is bracketed by Flow A, dated at 1,000 years, and Flow C, dated at 1,500 years, it is highly likely that the radiocarbon age of Flow B is not good, because it should be between 1,000 and 1,500 years.
“Once we determine that the radiocarbon results are consistent with stratigraphy, we have to calibrate the age. Calibration is necessary because, using tree-ring data from around the world, we know that the concentration of atmospheric carbon-14 varied from time to time, and we must account for this variability.
“Most ages are reported in years before present, with zero being A.D. 1950, before atmospheric atomic bomb testing altered the amount of carbon-14 in the air. If the age control is good enough based on stratigraphy, radiocarbon ages can be presented in terms of calendar years to facilitate comparison with non-geologic historical events.
“So, in geology (and other fields), charcoal can be useful for more than just grilling on the barbeque.”
See hvo.wr.usgs.gov/volcanowatch.
To read comments, add your own, and like this story, see Facebook. Follow us on Instagram and Twitter.
HAWAI`I COUNTY COUNCIL HOLDS its regular and committee meetings Wednesday. Full council meets at 9 a.m. Public Safety & Mass Transit Committee meets at 1 p.m.; Finance, 1:15 p.m.; Planning, 1:30 p.m.; Public Works & Parks & Recreation, 2 p.m.; and Governmental Relations & Economic Development, 2:45 p.m.
All meetings take place at Council Chambers in Hilo. Agendas and live-streaming are available at hawaii.county.gov.
Ka`u residents can participate via teleconferencing at Na`alehu State Office Building.
SUPPORT OUR SPONSORS AT PAHALAPLANTATIONCOTTAGES.COM AND KAUCOFFEEMILL.COM. KA`U COFFEE MILL IS OPEN SEVEN DAYS A WEEK.
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| See kaucalendar.com. |
