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J. P. Kauahikaua

Publications and source records attributed to J. P. Kauahikaua.

At least 19 recordsLinked to original sources
USGS2003

Kilauea east rift zone magmatism: An episode 54 perspective

On January 29 30, 1997, prolonged steady-state effusion of lava from Pu'u'O'o was briefly disrupted by shallow extension beneath Napau Crater, 1 4 km uprift of the active Kilauea vent. A 23-h-long eruption ( episode 54 ) ensued from fissures that were overlapping or en echelon with eruptive fissures formed during episode 1 in 1983 and those of earlier rift zone eruptions in 1963 and 1968. Combined geophysical and petrologic data for the 1994 1999 eruptive interval, including episode 54 , reveal a variety of shallow magmatic conditions that persist in association with prolonged rift zone eruption. Near-vent lava samples document a significant range in composition, temperature and crystallinity of pre-eruptive magma. As supported by phenocryst liquid relations and Kilauea mineral thermometers established herein, the rift zone extension that led to episode 54 resulted in mixture of near-cotectic magma with discrete magma bodies cooled to ≤1100°C. Mixing models indicate that magmas isolated beneath Napau Crater since 1963 and 1968 constituted 32 65% of the hybrid mixtures erupted during episode 54 . Geophysical measurements support passive displacement of open-system magma along the active east rift conduit into closed-system rift -reservoirs along a shallow zone of extension. Geophysical and petrologic data for early episode 55 document the gradual flushing of episode 54 related magma during magmatic recharge of the edifice.

Hawaii↗
USGS1998

The character of long-term eruptions: Inferences from episodes 50-53 of the Pu'u 'Ō'ō-Kūpaianaha eruption of Kīlauea volcano

The Pu'u 'Ō'ō-Kūpaianaha eruption on the east rift zone of Kīlauea began in January 1983. The first 9 years of the eruption were divided between the Pu'u 'Ō'ō (1983–1986) and Kūpaianaha (1986–1992) vents, each characterized by regular, predictable patterns of activity that endured for years. In 1990 a series of pauses in the activity disturbed the equilibrium of the eruption, and in 1991, the output from Kūpaianaha steadily declined and a short-lived fissure eruption broke out between Kūpaianaha and Pu'u 'Ō'ō. In February 1992 the Kūpaianaha vent died, and, 10 days later, eruptive episode 50 began as a fissure opened on the uprift flank of the Pu'u 'Ō'ō cone. For the next year, the eruption was marked by instability as more vents opened on the flank of the cone and the activity was repeatedly interrupted by brief pauses in magma supply to the vents. Episodes 50–53 constructed a lava shield 60 m high and 1.3 km in diameter against the steep slope of the Pu'u 'Ō'ō cone. By 1993 the shield was pockmarked by collapse pits as vents and lava tubes downcut as much as 29 m through the thick deposit of scoria and spatter that veneered the cone. As the vents progressively lowered, the level of the Pu'u 'Ō'ō pond also dropped, demonstrating the hydraulic connection between the two. The downcutting helped to undermine the prominent Pu'u 'Ō'ō cone, which has diminished in size both by collapse, as a large pit crater formed over the conduit, and by burial of its flanks. Intervals of eruptive instability, such as that of 1991–1993, accelerate lateral expansion of the subaerial flow field both by producing widely spaced vents and by promoting surface flow activity as lava tubes collapse and become blocked during pauses.

Bulletin of Volcanology↗
USGS1998

The probability of lava inundation at the proposed and existing Kulani prison sites

The State of Hawai`i has proposed building a 2,300-bed medium-security prison about 10 km downslope from the existing Kulani medium-security correctional facility. The proposed and existing facilities lie on the northeast rift zone of Mauna Loa, which last erupted in 1984 in this same general area. We use the best available geologic mapping and dating with GIS software to estimate the average recurrence interval between lava flows that inundate these sites. Three different methods are used to adjust the number of flows exposed at the surface for those flows that are buried to allow a better representation of the recurrence interval. Probabilities are then computed, based on these recurrence intervals, assuming that the data match a Poisson distribution. The probability of lava inundation for the existing prison site is estimated to be 11- 12% in the next 50 years. The probability of lava inundation for the proposed sites B and C are 2- 3% and 1-2%, respectively, in the same period. The probabilities are based on estimated recurrence intervals for lava flows, which are approximately proportional to the area considered. The probability of having to evacuate the prison is certainly higher than the probability of lava entering the site. Maximum warning times between eruption and lava inundation of a site are estimated to be 24 hours for the existing prison site and 72 hours for proposed sites B and C. Evacuation plans should take these times into consideration.

Open-File Report↗
USGS1997

Reevaluation of vesicle distributions in basaltic lava flows

A fundamental dichotomy in the study of basaltic lava flows is that observations of active flows are restricted to flow surfaces, yet older flows are often exposed only in vertical cross section. Cross-sectional exposures of an inflated basaltic sheet flow emplaced in Kalapana, Hawaii, from 1990 to 1991 provide an unusual opportunity to merge these two viewpoints, permitting the development of the internal structure of the flow to be viewed in the context of its known emplacement history. We demonstrate that fundamental features of the flow structure—a thick upper vesicular crust that diminishes downward in overall vesicularity, a dense flow interior, and a thin lower vesicular zone—are generated through syn-emplacement cooling of upper and lower flow crusts. Both the inverse correlation of overall vesicularity and vesicle size and the constant relative thickness of the upper vesicular zone are unique to inflated flows and permit a reinterpretation of flows previously interpreted to be ponded (rapidly emplaced). Identification of inflation, in turn, implies near-horizontal paleoslopes and permits estimates of flow duration based on upper flow crust thickness.

Geology↗
USGS1996

Use of precipitation and groundwater isotopes to interpret regional hydrology on a tropical volcanic island: Kilauea volcano area, Hawaii

Isotope tracer methods were used to determine flow paths, recharge areas, and relative age for groundwater in the Kilauea volcano area of the Island of Hawaii. A network of up to 66 precipitation collectors was emplaced in the study area and sampled twice yearly for a 3-year period. Stable isotopes in rainfall show three distinct isotopic gradients with elevation, which are correlated with trade wind, rain shadow, and highelevation climatological patterns. Temporal variations in precipitation isotopes are controlled more by the frequency of storms than by seasonal temperature fluctuations. Results from this study suggest that (1) sampling network design must take into account areal variations in rainfall patterns on islands and in continental coastal areas and (2) isotope/elevation gradients on other tropical islands may be predictable on the basis of similar climatology. Groundwater was sampled yearly in coastal springs, wells, and a few high-elevation springs. Areal contrasts in groundwater stable isotopes and tritium indicate that the volcanic rift zones compartmentalize the regional groundwater system, isolating the groundwater south of Kilauea's summit and rift zones. Part of the Southwest Rift Zone appears to act as a conduit for water from higher elevation, but there is no evidence for downrift flow in the springs and shallow wells sampled in the lower East Rift Zone.

Water Resources Research↗
USGS1995

Episode 49 of the Pu'u 'Ō'ō-Kūpaianaha eruption of Kilauea volcano-breakdown of a steady-state eruptive era

The Pu'u 'O'o-Kupaianaha eruption (1983-present) is the longest lived rift eruption of either Kilauea or neighboring Mauna Loa in recorded history. The initial fissure opening in January 1983 was followed by three years of episodic fire fountaining at the Pu'u 'O'o vent on Kilauea's east rift zone ∼19km from the summit (episodes 4–47). These spectacular events gave way in July 1986 to five and a half years of near-continuous, low-level effusion from the Kupaianaha vent, ∼ 3km to the cast (episode 48). A 49th episode began in November 1991 with the opening of a new fissure between Pu'u 'O'o and Kupaianaha. This three week long outburst heralded an era of more erratic eruptive behavior characterized by the shut down of Kupaianaha in February 1992 and subsequent intermittent eruption from vents on the west flank of Pu'u 'O'o (episodes 50 and 51). The events occurring over this period are due to progressive shrinkage of the rift-zone reservoir beneath the eruption site, and had limited impact on eruption temperatures and lava composition.

Hawaii↗
USGS1995

An isotope hydrology study of the Kilauea volcano area, Hawaii

Isotope tracer methods were used to determine flow paths, recharge areas, and relative age for ground water in the Kilauea volcano area on the Island of Hawaii. Stable isotopes in rainfall show three distinct isotopic gradients with elevation, which are correlated with trade-wind, rain shadow, and high-elevation climatological patterns. Temporal variations in isotopic composition of precipitation are controlled more by the frequency of large storms than b.y seasonal temperature fluctuations. Consistency in results between two separate areas with rainfall caused by tradewinds and thermally-driven upslope airflow suggests that isotopic gradients with elevation may be similar on other islands in the tradewind belt, especially the other Hawaiian Islands, which have similar climatology and temperature lapse rates. Areal contrasts in ground-water stable isotopes and tritium indicate that the volcanic ri~ zones compartmentalize the regional ground-water system. Tritium levels in ground water within and downgradient of Kilauea's ri~ zones indicate relatively long residence times. Part of Kilauea's Southwest Ri~ Zone appears to act as a conduit for water from higher elevation, but there is no evidence for extensive down-ri~ flow in the lower East Ri~ Zone.

Water-Resources Investigations Report↗
USGS1993

The hydrothermal-convection systems of kilauea: an historical perspective

Kilauea is one of only two basaltic volcanoes in the world where geothermal power has been produced commercially. Little is known about the origin, size and longevity of its hydrothermal-convection systems. We review the history of scientific studies aimed at understanding these systems and describe their commercial development. Geothermal energy is a controversial issue in Hawai'i, partly because of hydrogen sulfide emissions and concerns about protection of rain forests. ?? 1993.

Geothermics↗