Hawaiian Volcano Observatory

Research Article| March 01, 1994 Emplacement and inflation of pahoehoe sheet flows: Observations and measurements of active lava flows on Kilauea Volcano, Hawaii KEN HON; KEN HON 1U. S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 96718 Search for other works by this author on: GSW Google Scholar JIM KAUAHIKAUA; JIM KAUAHIKAUA 1U. S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 96718 Search for other works by this author on: GSW Google Scholar ROGER DENLINGER; ROGER DENLINGER 1U. S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 96718 Search for other works by this author on: GSW Google Scholar KEVIN MACKAY KEVIN MACKAY 2Victoria University of Wellington, Wellington, New Zealand Search for other works by this author on: GSW Google Scholar GSA Bulletin (1994) 106 (3): 351–370. https://doi.org/10.1130/0016-7606(1994)106<0351:EAIOPS>2.3.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation KEN HON, JIM KAUAHIKAUA, ROGER DENLINGER, KEVIN MACKAY; Emplacement and inflation of pahoehoe sheet flows: Observations and measurements of active lava flows on Kilauea Volcano, Hawaii. GSA Bulletin 1994;; 106 (3): 351–370. doi: https://doi.org/10.1130/0016-7606(1994)106<0351:EAIOPS>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Inflated pahoehoe sheet flows have a distinctive horizontal upper surface, which can be several hundred meters across, and are bounded by steep monoclinal uplifts. The inflated sheet flows we studied ranged from 1 to 5 m in thickness, but initially propagated as thin sheets of fluid pahoehoe lava, generally 20-30 cm thick. Individual lobes originated at outbreaks from the inflated front of a prior sheet-flow lobe and initially moved rapidly away from their source. Velocities slowed greatly within hours due to radial spreading and to depletion of lava stored within the source flow. As the outward flow velocity decreases, cooling promotes rapid crustal growth. At first, the crust behaves plastically as pahoehoe toes form. After the crust attains a thickness of 2-5 cm, it behaves more rigidly and develops enough strength to retain incoming lava, thus increasing the hydrostatic head at the flow front. The increased hydrostatic pressure is distributed evenly through the liquid lava core of the flow, resulting in uniform uplift of the entire sheet-flow lobe. Initial uplift rates are rapid (flows thicken to 1 m in 1-2 hours), but rates decline sharply as crustal thickness increases, and as outbreaks occur from the margins of the inflating lobe. One flow reached a final thickness of nearly 4 m after 350 hr. Inflation data define power-law curves, whereas crustal cooling follows square root of time relationships; the combination of data can be used to construct simple models of inflated sheet flows.As the flow advances, preferred pathways develop in the older portions of the liquid-cored flow; these pathways can evolve into lavatube systems within a few weeks. Formation of lava tubes results in highly efficient delivery of lava at velocities of several kilometers per hour to a flow front that may be moving 1-2 orders of magnitude slower. If advance of the sheet flow is terminated, the tube remains filled with lava that crystallizes in situ rather than draining to form the cave-like lava tubes commonly associated with pahoehoe flows.Inflated sheet flows from Kilauea and Mauna Loa are morphologically similar to some thick Icelandic and submarine sheet flows, suggesting a similar mechanism of emplacement. The planar, sheet-like geometry of flood-basalt flows may also result from inflation of sequentially emplaced flow lobes rather than nearly instantaneous emplacement as literal floods of lava. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Connecting caldera collapse The Kīlauea Volcano on the island of Hawai‘i erupted for 3 months in 2018. Neal et al. present a summary of the eruption sequence along with a variety of geophysical observations collected by the Hawaiian Volcano Observatory. The cyclic inflation, deflation, and eventual collapse of the summit was tied to lava eruption from lower East Rift Zone fissures. A total volume of 0.8 cubic kilometers of magma erupted, roughly the equivalent of 320,000 swimming pools, which matched the change in volume at the summit. Science , this issue p. 367

The sudden, catastrophic release of gas from Lake Nyos on 21 August 1986 caused the deaths of at least 1700 people in the northwest area of Cameroon, West Africa. Chemical, isotopic, geologic, and medical evidence support the hypotheses that (i) the bulk of gas released was carbon dioxide that had been stored in the lake's hypolimnion, (ii) the victims exposed to the gas cloud died of carbon dioxide asphyxiation, (iii) the carbon dioxide was derived from magmatic sources, and (iv) there was no significant, direct volcanic activity involved. The limnological nature of the gas release suggests that hazardous lakes may be identified and monitored and that the danger of future incidents can be reduced.

The 15 January 2022 climactic eruption of Hunga volcano, Tonga, produced an explosion in the atmosphere of a size that has not been documented in the modern geophysical record. The event generated a broad range of atmospheric waves observed globally by various ground-based and spaceborne instrumentation networks. Most prominent was the surface-guided Lamb wave (≲0.01 hertz), which we observed propagating for four (plus three antipodal) passages around Earth over 6 days. As measured by the Lamb wave amplitudes, the climactic Hunga explosion was comparable in size to that of the 1883 Krakatau eruption. The Hunga eruption produced remarkable globally detected infrasound (0.01 to 20 hertz), long-range (~10,000 kilometers) audible sound, and ionospheric perturbations. Seismometers worldwide recorded pure seismic and air-to-ground coupled waves. Air-to-sea coupling likely contributed to fast-arriving tsunamis. Here, we highlight exceptional observations of the atmospheric waves.

Research Article| November 01, 1992 Volcano growth and evolution of the island of Hawaii JAMES G. MOORE; JAMES G. MOORE 1U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar DAVID A. CLAGUE DAVID A. CLAGUE 2U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii 96718 Search for other works by this author on: GSW Google Scholar Author and Article Information JAMES G. MOORE 1U.S. Geological Survey, Menlo Park, California 94025 DAVID A. CLAGUE 2U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii 96718 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1992) 104 (11): 1471–1484. https://doi.org/10.1130/0016-7606(1992)104<1471:VGAEOT>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation JAMES G. MOORE, DAVID A. CLAGUE; Volcano growth and evolution of the island of Hawaii. GSA Bulletin 1992;; 104 (11): 1471–1484. doi: https://doi.org/10.1130/0016-7606(1992)104<1471:VGAEOT>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The seven volcanoes comprising the island of Hawaii and its submarine base are, in order of growth, Mahukona, Kohala, Mauna Kea, Hualalai, Mauna Loa, Kilauea, and Loihi. The first four have completed their shield-building stage, and the timing of this event can be determined from the depth of the slope break associated with the end of shield building, calibrated using the ages and depths of a series of dated submerged coral reefs off northwest Hawaii. The composition of lavas collected adjacent to these reefs helps to define the eruptive history of the various volcanic centers. The island of Hawaii has grown at an average rate of about 0.02 km2/yr for the past 600 k.y. and presently is close to its maximum size. Mahukona completed shield building about 465 ka; Kohala, 245 ka; Mauna Kea, 130 ka; and Hualalai, 130 ka. On each volcano, the transition from eruption of tholeiitic to alkalic lava occurs near the end of shield building. The larger volcanic systems (which stood more than 4 km above their shoreline at the end of shield building) change in composition before the end of shield building, and the smaller volcanoes change near or after the end of shield building, or never make the change to eruption of alkalic lava.The rate of southeastern (south 40° east) progression of the end of shield building (and hence the postulated movement rate of the Pacific plate over the Hawaiian hotspot) in the interval from Haleakala to Hualalai is about 13 cm/yr. Based on this rate and an average spacing of volcanoes on each loci line of 40-60 km, the volcanoes require about 600 thousand years to grow from the ocean floor (generally from a point on the southeastern submarine flank of the next older volcano of the same loci line) to the time of the end of shield building. They arrive at the ocean surface about midway through this period. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

We present a method for locating the source of seismic events on Piton de la Fournaise. The method is based on seismic amplitudes corrected for station site effects using coda site amplification factors. Once corrected, the spatial distribution of amplitudes shows smooth and simple contours for many types of events, including rockfalls, long‐period events and eruption tremor. On the basis of the simplicity of these distributions we develop inversion methods for locating their origins. To achieve this, the decrease of the amplitude as a function of the distance to the source is approximated by the decay either of surface or body waves in a homogeneous medium. The method is effective for locating rockfalls, long‐period events, and eruption tremor sources. The sources of eruption tremor are usually found to be located at shallow depth and close to the eruptive fissures. Because of this, our method is a useful tool for locating fissures at the beginning of eruptions.

Research Article| January 01, 1978 Petrologic evolution of the San Juan volcanic field, southwestern Colorado: Pb and Sr isotope evidence PETER W. LIPMAN; PETER W. LIPMAN 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 967182Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar BRUCE R. DOE; BRUCE R. DOE 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 967182Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar CARL E. HEDGE; CARL E. HEDGE 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 967182Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar THOMAS A. STEVEN THOMAS A. STEVEN 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 967182Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Author and Article Information PETER W. LIPMAN 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 967182Federal Center, Denver, Colorado 80225 BRUCE R. DOE 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 967182Federal Center, Denver, Colorado 80225 CARL E. HEDGE 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 967182Federal Center, Denver, Colorado 80225 THOMAS A. STEVEN 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 967182Federal Center, Denver, Colorado 80225 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1978) 89 (1): 59–82. https://doi.org/10.1130/0016-7606(1978)89<59:PEOTSJ>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation PETER W. LIPMAN, BRUCE R. DOE, CARL E. HEDGE, THOMAS A. STEVEN; Petrologic evolution of the San Juan volcanic field, southwestern Colorado: Pb and Sr isotope evidence. GSA Bulletin 1978;; 89 (1): 59–82. doi: https://doi.org/10.1130/0016-7606(1978)89<59:PEOTSJ>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Two distinct suites of igneous rocks occur within the San Juan volcanic field: an Oligocene suite of predominantly intermediate-composition lavas and breccias, with associated silicic differentiates erupted mainly as ash-flow tuffs, and a Miocene-Pliocene bimodal suite of silicic rhyolites and mafic alkalic lavas.The Oligocene volcanism, probably related to subduction along the western margin of the American plate, has chemical and isotopic characteristics indicative of complex interactions with Precambrian cratonic lithosphere. It also appears to record the rise, differentiation, and crystallization of a large composite batholith beneath the San Juan field. The earliest intermediate-composition lavas and breccias have major- and minor-element compositional patterns indicative of high-pressure fractionation and are relatively nonradiogenic in both Pb and Sr, suggesting significant interaction with lower crust of the American plate. The more silicic ash-flow tuffs show compositional evidence of low-pressure fractional crystallization and are more radiogenic in Pb and Sr — features thought to indicate significant shallow residency for the magmas and interaction with upper crust. Especially radiogenic Pb-isotope compositions of some of these rocks may reflect interactions between the magmas and convecting meteoric water rich in leached Pb, a process thought to have been even more important in forming associated hydrothermal ore deposits. Ore leads tend to be more radiogenic than associated rock leads.Many of the Miocene-Pliocene basaltic lavas seem to be mantle-derived lavas, similar to those of oceanic islands, but some anomalous xenocrystic basaltic andesites, containing relatively nonradiogenic lead, may have been slightly contaminated by lower crustal components. Rhyolitic lavas and intrusions of the bimodal suite are also nonradiogenic in Pb and Sr, in comparison with the Oligocene rhyolites, and do not appear to have interacted with Precambrian upper crust, probably because they erupted largely through the subvolcanic batholith. The Miocene-Pliocene rhyolites are best interpreted as partial melts of lower crust, with the thermal energy to initiate magma generation provided by concurrent basaltic volcanism. This content is PDF only. Please click on the PDF icon to access. 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Research Article| February 01, 1973 Flow of Lava into the Sea, 1969–1971, Kilauea Volcano, Hawaii JAMES G. MOORE; JAMES G. MOORE 1U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar R. L. PHILLIPS; R. L. PHILLIPS 1U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar RICHARD W. GRIGG; RICHARD W. GRIGG 2Hawaii Institute of Marine Biology, University of Hawaii, Honolulu, Hawaii 96822 Search for other works by this author on: GSW Google Scholar DONALD W. PETERSON; DONALD W. PETERSON 3U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 96718 Search for other works by this author on: GSW Google Scholar DONALD A. SWANSON DONALD A. SWANSON 3U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 96718 Search for other works by this author on: GSW Google Scholar Author and Article Information JAMES G. MOORE 1U.S. Geological Survey, Menlo Park, California 94025 R. L. PHILLIPS 1U.S. Geological Survey, Menlo Park, California 94025 RICHARD W. GRIGG 2Hawaii Institute of Marine Biology, University of Hawaii, Honolulu, Hawaii 96822 DONALD W. PETERSON 3U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 96718 DONALD A. SWANSON 3U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, Hawaii 96718 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1973) 84 (2): 537–546. https://doi.org/10.1130/0016-7606(1973)84<537:FOLITS>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation JAMES G. MOORE, R. L. PHILLIPS, RICHARD W. GRIGG, DONALD W. PETERSON, DONALD A. SWANSON; Flow of Lava into the Sea, 1969–1971, Kilauea Volcano, Hawaii. GSA Bulletin 1973;; 84 (2): 537–546. doi: https://doi.org/10.1130/0016-7606(1973)84<537:FOLITS>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Note: This paper is dedicated to Aaron and Elizabeth Waters on the occasion of Dr. Waters' retirement.Lava from the Mauna Ulu eruption on Kilauea Volcano entered the sea on the south coast of the Island of Hawaii three times from 1969 to 1971. Two of these flows were investigated underwater by divers, one while lava was actively flowing.The June 1969 flow entered the sea as a narrow flow of aa. Below sea level, the flow maintained continuity and flowed at least several hundred meters to a depth beyond 70 m. Several cylindrical flow lobes about 1 m in diameter and about 10 to 15 m long emerged from the side of the aa flow at a depth of about 25m.Underwater investigations, combined with subaerial observations, revealed that the March–May 1971 flow produced a distinct lava delta composed of subaerial pahoehoe lava resting on a submarine sequence of steeply dipping foreset-bedded volcanic sand and rubble that includes conformably dipping cylindrical lava tongues. Most of the pahoehoe streams pouring over the sea cliff are quenched and shattered to glassy sand and rubble that in turn is further fragmented by vigorous wave action and avalanching. In some places, however, larger pahoehoe flows maintain coherence across the cliff and through the surf zone to feed submarine lava tongues. Underwater, these active lava tongues emitted a roaring noise as lava flowed inside their outer black glassy walls. Periodically, cracks exposed the brightly incandescent lava within, and pillow-like buds and toes grew from the top and sides of the lava tongue. Only a small amount of steam was generated underwater. Water temperature close to the active tongues was elevated only 2.5°C. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Abstract We have studied 30 quenched tholeiitic lava flows recovered by 20 dredge hauls and one submersible dive along Puna Ridge, the submarine part of the East Rift Zone of Kilauea Volcano, Hawaii Glass grains from numerous additional flows were recovered in turbidite sands cored in the Hawaiian Trough. These quenched lavas document variable primary magma compositions; olivine and multiphase crystallization and fractionation; degassing; wall-rock stoping and assimilation; mixing in the crustal reservoir and the rift zone; entrainment of olivine xenocrysts from a hot, ductile, olivine cumulate body; and disruption of gabbro wallrocks in the rift zone. Glass grains in turbidite sands contain up to 15⋅0wt% MgO, in contrast to &amp;lt; 7⋅0wt% MgO for the sampled glass rinds on lavas. The most forsteritic olivine phenocryst (F090·7) is in equilibrium with primary Kilauea liquid containing an average 16⋅5 wt% MgO, but ranging from 13⋅4 to 18⋅4%. Lavas and glass grains have more restricted P2O5/K2O and TiO2/K2O than glass inclusions in olivine, because more diverse liquids trapped as glass inclusions are mixed and homogenized before eruption. Variable trace element compositions in glass grains and whole rocks indicate that the primary liquids form by partial melting of mantle sources retaining clinopyroxene and garnet. Orthopyroxene xenocrysts formed at moderate pressures provide evidence for a sub-crustal staging zone. Chromite and olivine crystallize in the crustal magma reservoir as the liquid cools from an average 1346°C to ∼1170°C. Low viscosities of the primary liquids (0·4 Pas) facilitate olivine settling, and the crystallized olivine forms an olivine cumulate body at the base of the reservoir. Olivine is deformed as the hot ductile dunite body flows down and away from the summit. This flow drives instability of the Hilina landslide on Kilauea. Dikes intrude the dunite, and magma flowing through the dikes disaggregates and entrains olivine xenocrysts in Puna Ridge magmas. Primary liquids pond at or near the base of Kilauea's crustal reservoir because they are denser than more fractionated liquids that occupy the upper parts of the reservoir. The sulfur and water contents of glass rinds indicate that fractionated liquids near the top of the reservoir degas at low pressure, a process that increases their density and causes them to sink to levels where they mix with resident undegassed, near-primary liquid. The fractionated liquids near the top of the magma reservoir acquire excess Cl, owing to assimilation of hydrothermally altered roofrocks. Magma flowing into the rift zone encounters and mixes with low-temperature, multiphase-fractionated melt. The mixed magmas typically contain rare orthopyroxene, plagioclase as sodic as andesine, olivine as fayalitic as F075 and Fe-rich augite derived from the fractionated magma. Magma flowing through dikes also dislodged fragments of gabbroic wallrocks that occur as xenoliths. The interrelations in the Kilauean submarine lavas between host glass and glass inclusion compositions, volatile contents and mineral chemistry reveal an extraordinarily complex sequence of petrogenetic processes and events that are difficult or impossible to determine in subaerial Kilauea lavas because of crystallization, reequilibration and degassing during or after their eruption.

Research Article| October 01, 1976 Caldera-collapse breccias in the western San Juan Mountains, Colorado PETER W. LIPMAN PETER W. LIPMAN 1U.S. Geological Survey, Hawaii Volcano Observatory, Hawaii National Park, Hawaii 96718 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1976) 87 (10): 1397–1410. https://doi.org/10.1130/0016-7606(1976)87<1397:CBITWS>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation PETER W. LIPMAN; Caldera-collapse breccias in the western San Juan Mountains, Colorado. GSA Bulletin 1976;; 87 (10): 1397–1410. doi: https://doi.org/10.1130/0016-7606(1976)87<1397:CBITWS>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract In four large Oligocene calderas in the western San Juan Mountains – Lake City, Silverton, San Juan, and Uncompahgre – spectacular breccias are intermixed with thick intracaldera ash-flow tuffs that accumulated during caldera collapse. These breccias are divided into two intergradational types: (1) mesobreccia in which numerous small clasts are visible within single outcrops and (2) megabreccia in which many clasts are so large that the fragmental nature of the deposit is obscure in many individual outcrops.In general, mesobreccia occurs as thin tabular deposits locally interlayered with upper parts of the intracaldera ash-flow accumulations; it is readily interpretable as resulting from small- to medium-sized rock falls and rock slides from the caldera walls. In contrast, megabreccia is dominant in the lower part of the caldera-filling sequence and contains only minor intermixed ash-flow material. Megabreccia is difficult to distinguish from pre-collapse caldera floor in places, but local lenses of welded tuff near the deepest stratigraphic levels exposed within the calderas indicate that these rocks are mostly megabreccia that resulted from major slumping and caving of caldera walls during the initial stages of caldera collapse. An especially large megabreccia unit within the San Juan and Uncompahgre calderas is here named the Picayune Megabreccia Member of the Sapinero Mesa Tuff.Megabreccias similar to those in the western San Juan calderas occur in other eroded collapse structures in the western United States, and the presence of such deposits may be useful guides to the roots of caldera structures in deeply eroded, highly altered, or structurally complex volcanic terranes. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

An electrochemical device was used to measure the fugacity of oxygen (fo(o2)) in holes drilled through the crust of Makaopuhi lava lake, Kilauea Volcano, Hawaii. Results obtained within 6 months of the lake formation show that log fo(o2) normally varies linearly with the reciprocal of the absolute temperature, and that chemical changes occurring in the cooling tholeiitic basalt are reflected in the fo(o2) values measured in the holes.

Teleseismic P wave arrival times recorded by a dense network of seismograph stations located on Kilauea volcano, Hawaii, are inverted to determine lateral variations in crust and upper mantle structure to a depth of 70 km. The crustal structure is dominated by relatively high velocities within the central summit complex and along the two radial rift zones, compared with the nonrift flank of the volcano. Both the mean crustal velocity contrast between summit and nonrift flank and the distribution of velocities agree well with results from crustal refraction studies. Comparison of the velocity structure with Bouguer gravity anomalies over the volcano through a simple physical model also gives excellent agreement. Mantle structure appears to be more homogeneous than crustals tructure. The root mean square velocity variation for the mantle averages only 1.5%, whereas variation within the crust exceeds 4%. The summit of Kilauea is underlain by normal velocity (8.1 km/s) material within the uppermost mantle (12-25 km), suggesting that large magma storage reservoirs are not present at this level and that the passageways from deeper sources must be quite narrow. No evidence is found for substantial volumes of partially molten rock (5%) within the mantle to depths of at least 40 km. Below about 30 km, low-velocity zones (1-2%) underlie the summits of Kilauea and nearby Mauna Loa and extend south of Kilauea into a broad offshore zone. Correlation of volcanic tremor source locations and persistent zones of mantle earthquakes with low-velocity mantle between 27.5- and 42.5-km depth suggeststh at a laterally extensive conduit system feeds magma to the volcanic summits from sources either at comparable depth or deeper within the mantle. The center of contemporary magmatic production and/or upwelling from deeper in the mantle appears to extend well to the south of the active volcanic summits, suggestingth at the Hawaiian Island chain is actively extending to the southeast.

Surface deformation caused by an intrusion and small eruption during June 17-19, 2007, along the East Rift Zone of Kilauea Volcano, Hawaii, was three-dimensionally reconstructed from radar interferograms acquired by the Advanced Land Observing Satellite (ALOS) phased-array type L-band synthetic aperture radar (SAR) (PALSAR) instrument. To retrieve the 3-D surface deformation, a method that combines multiple-aperture interferometry (MAI) and conventional interferometric SAR (InSAR) techniques was applied to one ascending and one descending ALOS PALSAR interferometric pair. The maximum displacements as a result of the intrusion and eruption are about 0.8, 2, and 0.7 m in the east, north, and up components, respectively. The radar-measured 3-D surface deformation agrees with GPS data from 24 sites on the volcano, and the root-mean-square errors in the east, north, and up components of the displacement are 1.6, 3.6, and 2.1 cm, respectively. Since a horizontal deformation of more than 1 m was dominantly in the north-northwest-south-southeast direction, a significant improvement of the north-south component measurement was achieved by the inclusion of MAI measurements that can reach a standard deviation of 3.6 cm. A 3-D deformation reconstruction through the combination of conventional InSAR and MAI will allow for better modeling, and hence, a more comprehensive understanding, of the source geometry associated with volcanic, seismic, and other processes that are manifested by surface deformation.

Caldera-forming eruptions are among Earth's most hazardous natural phenomena, yet the architecture of subcaldera magma reservoirs and the conditions that trigger collapse are poorly understood. Observations from the formation of a 0.8-cubic kilometer basaltic caldera at Kīlauea Volcano in 2018 included the draining of an active lava lake, which provided a window into pressure decrease in the reservoir. We show that failure began after <4% of magma was withdrawn from a shallow reservoir beneath the volcano's summit, reducing its internal pressure by ~17 megapascals. Several cubic kilometers of magma were stored in the reservoir, and only a fraction was withdrawn before the end of the eruption. Thus, caldera formation may begin after withdrawal of only small amounts of magma and may end before source reservoirs are completely evacuated.

We report a CO 2 emission rate of 8500 metric tons per day (t d −1 ) for the summit of Kīlauea Volcano, several times larger than previous estimates. It is based on three sets of measurements over 4 years of synchronous SO 2 emission rates and volcanic CO 2 /SO 2 concentration ratios for the summit correlation spectrometer (COSPEC) traverse. Volcanic CO 2 /SO 2 for the traverse is representative of the global ratio for summit emissions. The summit CO 2 emission rate is nearly constant, despite large temporal variations in summit CO 2 /SO 2 and SO 2 emission rates. Summit CO 2 emissions comprise most of Kīlauea's total CO 2 output (∼9000 t d −1 ). The bulk CO 2 content of primary magma determined from CO 2 emission and magma supply rate data is ∼0.70 wt %. Most of the CO 2 is present as exsolved vapor at summit reservoir depths, making the primary magma strongly buoyant. Turbulent mixing with resident reservoir magma, however, prevents frequent eruptions of buoyant primary magma in the summit region. CO 2 emissions confirm that the magma supply enters the edifice through the summit reservoir. A persistent several hundred parts per million CO 2 anomaly arises from the entry of magma into the summit reservoir beneath a square kilometer area east of Halemaumau pit crater. Since most of the CO 2 in primary magma is degassed in the summit, the summit CO 2 emission rate is an effective proxy for the magma supply rate. Both scrubbing of SO 2 and solubility controls on CO 2 and S in basaltic melt cause high CO 2 /SO 2 in summit emissions and spatially uncorrelated distributions of CO 2 and SO 2 in the summit plume.

Research Article| February 01, 1993 Vesiculation of basaltic magma during eruption Margaret T. Mangan; Margaret T. Mangan 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii 96718 Search for other works by this author on: GSW Google Scholar Katharine V. Cashman; Katharine V. Cashman 2Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403 Search for other works by this author on: GSW Google Scholar Sally Newman Sally Newman 3Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125 Search for other works by this author on: GSW Google Scholar Author and Article Information Margaret T. Mangan 1U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii 96718 Katharine V. Cashman 2Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403 Sally Newman 3Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1993) 21 (2): 157–160. https://doi.org/10.1130/0091-7613(1993)021<0157:VOBMDE>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Margaret T. Mangan, Katharine V. Cashman, Sally Newman; Vesiculation of basaltic magma during eruption. Geology 1993;; 21 (2): 157–160. doi: https://doi.org/10.1130/0091-7613(1993)021<0157:VOBMDE>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Vesicle size distributions in vent lavas from the Pu'u'O'o-Kupaianaha eruption of Kilauea volcano are used to estimate nucleation and growth rates of H2O-rich gas bubbles in basaltic magma nearing the earth's surface (≤120 m depth). By using well-constrained estimates for the depth of volatile exsolution and magma ascent rate, nucleation rates of 35.9 events ⋅ cm-3 ⋅ s-1 and growth rates of 3.2 x 10-4 cm/s are determined directly from size-distribution data. The results are consistent with diffusion-controlled growth as predicted by a parabolic growth law. This empirical approach is not subject to the limitations inherent in classical nucleation and growth theory and provides the first direct measurement of vesiculation kinetics in natural settings. In addition, perturbations in the measured size distributions are used to examine bubble escape, accumulation, and coalescence prior to the eruption of magma. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Campaign Global Positioning System (GPS) measurements from 1990 to 1996 are used to calculate surface displacement rates on Kilauea Volcano, Hawaii. The GPS data show that the south flank of the volcano, which has generated several large earthquakes in the past 3 decades, is displacing at up to ∼8 cm/yr to the south‐southeast. The summit and rift zones are subsiding, with maximum subsidence rates of ∼8 cm/yr observed a few kilometers south of the summit caldera. Elastic dislocation modeling of the GPS data suggests that the active sources of deformation include deep rift opening along the upper east and east rift zone, fault slip along a subhorizontal fault near the base of the volcano, and deflation near the summit caldera. A nonlinear optimization algorithm was used to explore the parameter space and to find the best fitting source geometry. There is a broad range of model geometries that fit the data reasonably well. However, certain models can be ruled out, including those that have shallow rift opening or shallow fault slip. Some offshore, aseismic slip on a fault plane that dips between 25° northnorthwest and 8° south‐southeast is required. Best fitting slip and rift opening rates are 23–28 cm/yr, although rates as low as 10 cm/yr are permitted by the data.

Several polymerase chain reaction (PCR)-based methods have recently been developed for diagnosing malarial infections in both birds and reptiles, but a critical evaluation of their sensitivity in experimentally-infected hosts has not been done. This study compares the sensitivity of several PCR-based methods for diagnosing avian malaria (Plasmodium relictum) in captive Hawaiian honeycreepers using microscopy and a recently developed immunoblotting technique. Sequential blood samples were collected over periods of up to 4.4 yr after experimental infection and rechallenge to determine both the duration and detectability of chronic infections. Two new nested PCR approaches for detecting circulating parasites based on P. relictum 18S rRNA genes and the thrombospondin-related anonymous protein (TRAP) gene are described. The blood smear and the PCR tests were less sensitive than serological methods for detecting chronic malarial infections. Individually, none of the diagnostic methods was 100% accurate in detecting subpatent infections, although serological methods were significantly more sensitive (97%) than either nested PCR (61-84%) or microscopy (27%). Circulating parasites in chronically infected birds either disappear completely from circulation or to drop to intensities below detectability by nested PCR. Thus, the use of PCR as a sole means of detection of circulating parasites may significantly underestimate true prevalence.

Research Article| October 01, 1997 Imaging the crustal magma sources beneath Mauna Loa and Kilauea volcanoes, Hawaii Paul G. Okubo; Paul G. Okubo 1U.S. Geological Survey, Hawaiian Volcano Observatory, P.O. Box 51, Hawaii National Park, Hawaii 96718 Search for other works by this author on: GSW Google Scholar Harley M. Benz; Harley M. Benz 2U.S. Geological Survey, Box 25046, M.S. 967, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Bernard A. Chouet Bernard A. Chouet 3U.S. Geological Survey, M.S. 977, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Author and Article Information Paul G. Okubo 1U.S. Geological Survey, Hawaiian Volcano Observatory, P.O. Box 51, Hawaii National Park, Hawaii 96718 Harley M. Benz 2U.S. Geological Survey, Box 25046, M.S. 967, Denver, Colorado 80225 Bernard A. Chouet 3U.S. Geological Survey, M.S. 977, 345 Middlefield Road, Menlo Park, California 94025 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1997) 25 (10): 867–870. https://doi.org/10.1130/0091-7613(1997)025<0867:ITCMSB>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Paul G. Okubo, Harley M. Benz, Bernard A. Chouet; Imaging the crustal magma sources beneath Mauna Loa and Kilauea volcanoes, Hawaii. Geology 1997;; 25 (10): 867–870. doi: https://doi.org/10.1130/0091-7613(1997)025<0867:ITCMSB>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Three-dimensional seismic P-wave traveltime tomography is used to image the magma sources beneath Mauna Loa and Kilauea volcanoes, Hawaii. High-velocity bodies (>6.4 km/s) in the upper 9 km of the crust beneath the summits and rift zones of the volcanoes correlate with zones of high magnetic intensities and are interpreted as solidified gabbro-ultramafic cumulates from which the surface volcanism is derived. The proximity of these high-velocity features to the rift zones is consistent with a ridge-spreading model of the volcanic flank. Southeast of the Hilina fault zone, along the south flank of Kilauea, low-velocity material (<6.0 km/s) is observed extending to depths of 9–11 km, indicating that the Hilina fault may extend possibly as deep as the basal decollement. Along the southeast flank of Mauna Loa, a similar low-velocity zone associated with the Kaoiki fault zone is observed extending to depths of 6–8 km. These two upper crustal low-velocity zones suggest common stages in the evolution of the Hawaiian shield volcanoes in which these fault systems are formed as a result of upper crustal deformation in response to magma injection within the volcanic edifice. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

A magnitude 7.2 earthquake in 1975 caused the south flank of Kilauea Volcano, Hawaii, to move seaward in response to slippage along a deep fault. Since then, a large part of the volcano's edifice has been adjusting to this perturbation. The summit of Kilauea extended at a rate of 0.26 meter per year until 1983, the south flank uplifted more than 0.5 meter, and the axes of both the volcano's rift zones extended and subsided; the summit continues to subside. These ground-surface motions have been remarkably steady and much more widespread than those caused by either recurrent inflation and deflation of the summit magma chamber or the episodic propagation of dikes into the rift zones. Kilauea's magmatic system is, therefore, probably deeper and more extensive than previously thought; the summit and both rift zones may be underlain by a thick, near vertical dike-like magma system at a depth of 3 to 9 kilometers.