Hawaiian Volcanoes Research Articles

A Comparison of the Magmatic Evolution of Pacific Intraplate Volcanoes: Constraints on Melting in Mantle Plumes

The interaction of deep mantle plumes with lithospheric plates is one fundamental concept of plate tectonics. Based on observations mainly made on the Hawaiian volcanoes the compositional evolution of hotspot volcanoes is believed to reflect the variation of partial melting and source composition as the plate moves across the different melting zones of the mantle plume. The model predicts the formation of several magmatic stages that differ in composition. In order to test this model, we compare published compositional and age data from the intraplate volcanoes of the Hawaii, Society, Marquesas and Samoa hotspots on the older part of the Pacific Plate. The compiled data indicate that most volcanoes display variations within and between several magmatic series, and in most cases the more evolved lavas are associated with the voluminous shield stage. The Hawaiian volcanoes show up to four different series ranging from tholeiites to nephelinites/melilitites, whereas the other hotspots mainly erupt two magmatic series consisting of transitional basalts and basanites. Submarine preshield stages at the Society and Marquesas hotspots resemble those observed at Hawaii. The large variation of primitive magmas in the Hawaiian plume as opposed to the other Pacific intraplate systems may reflect the higher temperatures, higher buoyancy flux and extreme chemical heterogeneity at Hawaii. The shield stage activity at all four hotspots lasts for 1 million years indicating similar widths of the melting zone, although the temperatures of the distinct mantle plumes vary considerably. The relatively depleted shield stage magmatism typically overlaps by ~200 kyrs with the formation of the more enriched postshield magmas indicating that the two melting and magma ascent systems exist contemporaneously.

Beyond Cumulative Sum Charting in Non-Stationarity Detection and Estimation

In computer science, stochastic processes, and industrial engineering, stationarity is often taken to imply a stable, predictable flow of events and non-stationarity, consequently, a departure from such a flow. Efficient detection and accurate estimation of non-stationarity are crucial in understanding the evolution of the governing dynamics. Pragmatic considerations include protecting human lives and property in the context of devastating processes such as earthquakes or hurricanes. Cumulative Sum (CUSUM) charting, the prevalent technique to weed out such non-stationarities, suffers from assumptions on a priori knowledge of the pre and post-change process parameters and constructs such as time discretization. In this paper, we have proposed two new ways in which non-stationarity may enter an evolving system - an easily detectable way, which we term strong corruption, where the post-change probability distribution is deterministically governed, and an imperceptible way which we term hard detection, where the post-change distribution is a probabilistic mixture of several densities. In addition, by combining the ordinary and switched trend of incoming observations, we develop a new trend ratio statistic in order to detect whether a stationary environment has changed. Surveying a variety of distance metrics, we examine several parametric and non-parametric options in addition to the established CUSUM and find that the trend ratio statistic performs better under the especially difficult scenarios of hard detection. Simulations (both from deterministic and mixed inter-event time densities), sensitivity-specificity type analyses, and estimated time of change distributions enable us to track the ideal detection candidate under various non-stationarities. Applications on two real data sets sampled from volcanology and weather science demonstrate how the estimated change points are in agreement with those obtained in some of our previous works, using different methods. Incidentally, this study sheds light on the inverse nature of dependence between the Hawaiian volcanoes Kilauea and Mauna Loa and demonstrates how inhabitants of the now-restless Kilauea may be relocated to Mauna Loa to minimize the loss of lives and moving costs.

Tragic Aftermath of Californian Jungle Fire and Hawaiian Volcano Outburst, a Warning about Persistently Rising Global Warming, Resulting into High Rated Disaster’s Chain

Earthglobe is almost at flash point with respect to global heat contents and temperature and any sizeable further addition of heat to its environment will result into huge disaster of life, property and infrastructure at multiple locations on the globe. The recent example of this is the aftermath of Cali-fornian forest fires (2017-2018) and Hawaii volcano eruption as elaborated in this treatise. This has resulted into 7 main catastrophic events over the Earth globe in its first round, while in 2nd round, all the previous same 7 or similar event in the same or an area close to it are repeated with one more event added in the list. These wildfires add large quantity of heat directly to the globe and even more through abstraction of out going global heat radiation by their generated green house gasses, pollution and soot. The 2nd round is perhaps also supported by Hawaii volcanic eruption. The 3rd round has mainly completed and few expected events are yet in pipe line, but California jungle fire of November 2018 has strengthened its attacks again. The mechanics and tracks of its attacks with pulled in of its allies has been elaborated in this work with role of this wildfire and its all children; heat, soot, pollution and green house gasses in possible boast of global heat contents and temperature. It is observed that disastrous aftermath from all such heating events in the north are contained mainly in Northern Hemisphere, while contrary to this; some of such events in the south have hard strikes on the North. It is requested that Global heat contents rise, jungle fire and volcanic eruptions must be completely stopped by all means because this causes widespread disaster mainly over the tropical regions of Globe as experienced from Californian Jungle Fire.

Measuring SO2 Emission Rates at Kīlauea Volcano, Hawaii, Using an Array of Upward-Looking UV Spectrometers, 2014–2017

The Hawaiian Volcano Observatory uses an array of ten fixed, upward-looking ultraviolet spectrometer systems to measure SO2 emission rates at 10-second sample intervals from the Kīlauea summit. We present Kīlauea SO2 emission rates from the volcano’s summit and Middle East Rift Zone during 2014-2017 and discuss the major sources of error for these measurements. Due to the wide range of SO2 emissions encountered at the summit vent, we used a variable wavelength spectral analysis range to accurately quantify both high and low SO2 column densities. We present case studies comparing the measured emission rates from the fixed spectrometer array to independent road and helicopter-based traverse measurements and evaluate the magnitudes and sources of uncertainties for each method. To address the challenge of obtaining accurate plume speed measurements, we examine ground-based wind-speed, plume speed tracking via spectrometer, and SO2 camera derived plume speeds. Our analysis shows that 1) the summit array column densities calculated using a dual fit window, are within -6 to +22% of results obtained with a variety of other conventional and experimental retrieval methods 2) emission rates calculated from the summit array located ~3 km downwind of the Overlook vent provide the best, practical estimate of summit SO2 release under normal trade wind conditions 3) ground-based anemometer wind speeds are 22% less than plume speeds determined by cross-correlation of plume features 4) our best estimate of average Kīlauea SO2 release for 2014-2017 is 5100 t/d, which is comparable to the space-based OMI emissions of 5518 t/d 5) short-term variability of SO2 emissions reflect Kīlauea lava lake dynamics.

The 2018 rift eruption and summit collapse of Kīlauea Volcano.

In 2018, Kīlauea Volcano experienced its largest lower East Rift Zone (LERZ) eruption and caldera collapse in at least 200 years. After collapse of the Pu'u 'Ō'ō vent on 30 April, magma propagated downrift. Eruptive fissures opened in the LERZ on 3 May, eventually extending ~6.8 kilometers. A 4 May earthquake [moment magnitude (M w) 6.9] produced ~5 meters of fault slip. Lava erupted at rates exceeding 100 cubic meters per second, eventually covering 35.5 square kilometers. The summit magma system partially drained, producing minor explosions and near-daily collapses releasing energy equivalent to M w 4.7 to 5.4 earthquakes. Activity declined rapidly on 4 August. Summit collapse and lava flow volume estimates are roughly equivalent-about 0.8 cubic kilometers. Careful historical observation and monitoring of Kīlauea enabled successful forecasting of hazardous events.

Dust on a Hawaiian volcano: A regional model using field measurements to estimate transport and deposition

AbstractThe western slopes of Hawaii's Mauna Kea volcano are mantled by fine‐grained soils, the record of volcanic airfall and eolian deposition. Where exposed, strong winds transport this sediment across West Hawaii, affecting tourism and local communities with decreased air and water quality. Operations on US Army's Ke'amuku Maneuver Area (KMA) have the potential to increase dust flux from these deposits. The USGS established 18 ground monitoring sites and sampling locations surrounding KMA. For over 3 years, each station measured vertical and horizontal dust flux, while co‐located anemometers measured wind speed and direction. We used these datasets to develop a parsimonious regional model for dust supply and transport to assess whether KMA is a net dust sink or source.We found that dust transport is most highly correlated with threshold wind speeds of 8 m/s. We used this value as the regional average threshold wind speed for dust entrainment. Using a model that partitions measured horizontal dust flux into inward‐ and outward‐directed components, we estimate that KMA is currently a net dust sink. Geochemical analysis of dust samples illustrates that local organics and carbonate make up 64% of dust mass, the remainder being volcanic silt and fine sand. Measured vertical dust deposition rates of 0.006 mm/yr are similar to 0.004 mm/yr of deposition predicted from taking the divergence of dust across KMA's boundary. These rates are low compared with pre‐historic rates of ~0.2–0.3 mm/yr, from radiocarbon dating of buried soils.KMA's soils record persistent deposition over millennia, at rates that imply episodic dust storms. Such events created a soil‐mantled landscape in the middle of a largely Pleistocene rocky landscape. A substantial portion of fine‐grained soils in other leeward Hawaiian Island landscapes may have formed from similar eolian deposition, and not direct weathering of parent rock. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Long-Term Subsidence in Lava Fields at Piton de la Fournaise Volcano Measured by InSAR: New Insights for Interpretation of the Eastern Flank Motion

Long-term deformation often occurs in lava fields at volcanoes after flow emplacements. The investigation and interpretation of deformation in lava fields is one of the key factors for the assessment of volcanic hazards. As a typical Hawaiian volcano, Piton de la Fournaise volcano’s (La Réunion Island, France) main eruptive production is lava. Characteristics of the lava flows at Piton de la Fournaise, including the geometric parameters, location, and elevation, have been investigated by previous studies. However, no analysis focusing on the long-term post-emplacement deformation in its lava fields at a large spatial extent has yet been performed. One of the previous studies revealed that the post-emplacement lava subsidence played a role in the observed Eastern Flank motion by conducting a preliminary investigation. In this paper, an InSAR time series analysis is performed to characterize the long-term deformation in lava fields emplaced between 1998 and 2007 at Piton de la Fournaise, and to conduct an in-depth investigation over the influence of post-emplacement lava subsidence processes on the instability of the Eastern Flank. Results reveal an important regional difference in the subsidence behavior between the lava fields inside and outside of the Eastern Flank Area (EFA), which confirms that, in addition to the post-lava emplacement processes, other processes must have played a role in the observed subsidence in the EFA. The contribution of other processes is estimated to be up to ~78%. The spatial variation of the observed displacement in the EFA suggests that a set of active structures (like normal faults) could control a slip along a pre-existing structural discontinuity beneath the volcano flank. This study provides essential insights for the interpretation of the Eastern Flank motion of Piton de la Fournaise.

Sheet intrusions and deformation of Piton des Neiges, and their implication for the volcano-tectonics of La Réunion

To understand the volcano-tectonic history of Piton des Neiges (the dormant volcano of La Réunion), we measured in the field the orientation of sheeted intrusions and deformation structures, and interpreted the two datasets separately with a paleostress inversion. Results show that the multiple proposed rift zones may be simplified into three trends: (1) a N30°E, 5km wide linear rift zone running to the south of the edifice, active in the shield building (≥2.48–0.43Ma) and terminal stages (190–22ka); (2) a curved N110 to N160°E rift zone, widening from 5km to 10km toward the NW flank, essentially active during the early emerged shield building (≥1.3Ma); and (3) two sill zones, ≤1km thick in total, in the most internal parts of the volcano, active in the shield building and terminal stages.In parallel, deformation structures reveal that the tectonics of the edifice consisted in three end-member stress regimes sharing common stress axes: (1) NW-SE extension affecting in priority the south of the edifice near the N30°E rift zone; (2) NNE-SSW extension on the northern half of the volcano near the N110-160°E rift zone; (3) compression occurring near the sill zones, with a NE-SW or NW-SE maximum principal stress. These three stress regimes are spatially correlated and mechanically compatible with the injection trends.Combined together, our data show that the emerged Piton des Neiges underwent sector spreading delimited by perpendicular rift zones, as observed on Piton de la Fournaise (the active volcano of La Réunion). Analogue experiments attribute such sector spreading to brittle edifices built on a weaker substratum. We therefore conclude that La Réunion volcanoes are both brittle, as opposed to Hawaiian volcanoes or Mount Etna whose radial spreading is usually attributed to a ductile body within the edifices.

A Quantitative Insight into the Dependence Dynamics of the Kilauea and Mauna Loa Volcanoes, Hawaii

Hawaiian volcanoes such as Kilauea and Mauna Loa have drawn the attention of researchers for quite some time and numerous theories abound hinting at a possible inverse relationship between the two. Most of these analyses are intrinsically qualitative and are bereft of data-driven statistical justification. The present work attempts to address this issue adopting a more mathematical approach and endeavours to examine the existence of such a relationship through the novel use of a smoothing statistic termed as the empirical recurrence rates ratio. Additionally, it is shown that useful knowledge about the possible interplay between these two volcanoes is coded into this single statistic and based on it; construction of new dependence measures such as the two introduced, becomes simpler and much more intuitive. The recent decade is witnessing an increased activity of Kilauea and the methods proposed here can be successfully implemented to safeguard human lives and property against the unpredictable advances of all-engulfing molten lava flow.

Volcanic evolution of Moloka‘i, Hawai‘i: Implications for the shield to postshield transition in Hawaiian volcanoes

New mapping, geochronology and petrological investigations reveal that the two volcanoes of the island of Moloka‘i, Hawai‘i exhibit striking contrasts in composition and volcanic production in the waning stages of their activity. Postshield lava extrusion on West Moloka‘i produced less than 1km3 of alkalic basalt and hawaiite, most likely in less than 100k.y, beginning ~1.8Ma. West Moloka‘i is unique among Hawaiian volcanoes that reached the postshield stage of evolution in lacking a protracted period of transitional volcanism in the late shield stage. Petrological modeling indicates that volatile-poor (<0.5 wt % H2O) West Moloka‘i postshield magmas evolved in reservoirs in the upper mantle, 20-26km beneath the summit. In contrast, following a protracted transitional period, East Moloka‘i extruded postshield magmas ranging from hawaiite to benmoreite that evolved in magma reservoirs lying within the crust, 11- 17km beneath the summit. Parental magmas to the East Moloka‘i postshield were hydrous and enriched in phosphorous and Sr (2.5 wt % P2O5, 2500 ppm Sr at 6 wt % MgO, 45 wt % SiO2), a magma type known previously only from Kohala volcano. Although the overall volume of East Moloka‘i volcano is less than that of West Moloka‘i, its proportion of postshield extrusives is greater by a factor of 8, and its postshield volumetric production rate (~155km3/m.y.) is greater than that at West Moloka‘i by a factor of 3. The lower volume and deeper magmatic evolution of the West Moloka‘i postshield compared to that of East Moloka‘i is consistent with a thermally controlled relationship between magma supply, as inferred from volcanic production rate, and magma reservoir depth.

Nickel variability in Hawaiian olivine: Evaluating the relative contributions from mantle and crustal processes

Olivine in Hawaiian tholeiitic lavas have high NiO at given forsterite (Fo) contents (e.g., 0.25–0.60 wt% at Fo 88 ) compared to MORB (e.g., 0.10–0.28 wt% at Fo 88 ). This difference is commonly related to source variables such as depth and temperature of melting and/or lithology. Hawaiian olivine NiO contents are also highly variable and can range from 0.25–0.60 wt% at a given Fo. Here we examine the effects of crustal processes (fractional crystallization, magma mixing, diffusive re-equilibration) on the Ni content in olivine from Hawaiian basalts. Olivine compositions for five major Hawaiian volcanoes can be subdivided at ≥Fo 88 into high-Ni (0.25–0.60 wt% NiO; Ko‘olau, Mauna Loa, and Mauna Kea) and low-Ni (0.25–0.45 wt% NiO; Kīlauea and Lō‘ihi), groups that are unrelated to major isotopic trends (e.g., Loa and Kea). Within each group, individual volcanoes show up to 2.5× variation in olivine NiO contents at a given Fo. Whole-rock Ni contents from Ko‘olau, Mauna Loa, Mauna Kea, and Kīlauea lavas overlap significantly and do not correlate with differences in olivine NiO contents. However, inter-volcano variations in parental melt polymerization (NBO/T) and nickel partition coefficients ( D Ni Ol / melt ) , caused by variable melt SiO 2 , correlate with observed differences in olivine NiO at Fo 90 , indicating that an olivine-free source lithology does not produce the inter-volcano groups. Additionally, large intra-volcano variations in olivine NiO can occur with minimal variation in lava SiO 2 and NBO/T. Minor variations in parental melt NiO contents (0.09–0.11 wt%) account for the observed range of NiO in ≥Fo 88 olivine. High-precision electron microprobe analyses of olivine from Kīlauea eruptions (1500–2010 C.E.) show that the primary controls on 88 olivine NiO contents are fractional crystallization, magma mixing, and diffusive re-equilibration. Core-rim transects of normally zoned olivine crystals reveal marked differences in Fo and NiO zoning patterns that cannot be related solely to fractional crystallization. These Fo-NiO profiles usually occur in olivine with 88 and are common in mixed magmas, although they are not restricted to lavas with obvious petrographic signs of mixing. Three-dimensional numerical diffusion models show that diffusive re-equilibration decouples the growth zoning signatures of faster diffusing Fe-Mg (Fo) from the somewhat slower Ni. This diffusive “decoupling” overprints the chemical relationships of Fe-Mg, Ni, and Mn inherited from crystal growth and influences the calculated fraction of pyroxenite-derived melt (Xpx). Sections of numerical olivine that have been affected by diffusive re-equilibration indicate that larger phenocrysts (800 μm along c -axis) are >50% more likely to preserve original Xpx compared to smaller phenocrysts (400 μm along c -axis) which rarely (6%) recover original Xpx. Sections that are parallel or sub-parallel to the c -axis and/or pass near the core of the crystal best preserve growth signatures. Thus, diffusive re-equilibration, crystal size, and sectioning effects can strongly influence the characterization of mantle source lithologies for Hawaiian volcanoes.

How old is Kīlauea Volcano (Hawai‘i)? Insights from 40Ar/39Ar dating of the 1.7-km-deep SOH-1 core

Abstract Reliable estimates for lava accumulation rates are essential for interpreting magma fluxes to intraplate volcanoes and inferring the thermal and compositional structure of mantle plumes. Kīlauea Volcano’s (Hawai‘i) 1.7-km-deep SOH-1 scientific drill hole provides an opportunity to assess the lava accumulation rate and duration of the early shield stage for Hawaiian volcanoes. New 40Ar/39Ar ages were determined for four SOH-1 tholeiitic samples. Combining these results with two previous 40Ar/39Ar ages and the age of the drill-site surface flow, and correcting sample depth to remove intervening dikes, yields a good correlation (R2 = 0.97) for a 4.4 m/k.y. accumulation rate, which may have increased to 5.9 m/k.y. during the last 50 k.y. These rates contrast with a predicted 40% decrease during the last 200 k.y. from a simple shield volcano growth model. Mauna Loa, a massive shield volcano that buttresses the north flank of Kīlauea, may have contributed to this nearly constant lava accumulation rate. Extending the correlation to the base of the SOH-1 core indicates that Kīlauea’s tholeiitic volcanism probably started by 240 ka. Assuming an ∼400 k.y. duration for the preshield stage, Kīlauea is much older than some previous estimates (ca. 600 ka versus 150–275 ka) and has been vigorously erupting tholeiitic lavas for at least the past 200 k.y. During this period, it has been competing with Mauna Loa for the higher-temperature output of the Hawaiian mantle plume, which is contrary to previous models. New models that assess the magmatic output and thermal history of the Hawaiian mantle plume need to consider a steep increase in magma supply during the transition from preshield to shield stages to explain the near-constant lava accumulation rate during early shield growth.

The Wild Beckons

The Wild Beckons Katie James (bio) Wild Things Jaimee Wriston Colbert BkMk Press www.newletters.org/bkmk-books/wild-things 218 Pages; Print, $15.95 In her newest collection of short stories Wild Things, Jaimee Wriston Colbert features courageous survivors of a world teetering on the edge of extinction. "We haven't hit invisible yet," says Birdie in "Gravity," who goes on to describe how her town and the rest of Upstate New York is in peril after robotics and outsourcing close down blue collar manufacturing and factory jobs and environmental regulations run lax. These are characters trapped amid the blight and decay of a rural locale, where jobs are as endangered as the species that inhabit the area surrounding the Susquehanna River and despair permeates the atmosphere like pollution. And yet they cling on, desperately, like the Ohia tree in "Things Blow Up," growing on the side of a Hawaiian volcano, it's roots reaching down, down and gripping the earth for stability amid a rupturing environment. Colbert has created a masterpiece of short stories in which the vulnerability of all life is exposed and loneliness reigns supreme. Each of her narrating characters feel themselves to be outsiders to the world that holds them captive, and yet she shows their interconnectivity in a way that disputes how these characters see themselves situated in the world. This isn't to say that their feelings of isolation are not authentic; in fact, the sheer desperation they face and the loneliness they endure reflects the most universal of human experiences and allows for an authenticity that writers strive to capture and that Colbert incorporates with immense success. Part of the brilliance of this collection, however, is how the stories are interwoven. Each character is a story—seemingly isolated—and yet all make up a larger community that establishes a novel of sorts in which, while not necessarily sequential, the stories are linked. The main character of one story appears momentarily as a passing character in another story, exposing a character's life from a perspective outside their own own. In effect, one's personal story becomes a linked backstory to another character when the context widens, conveying a communal wholeness to the brokenness that occupies these characters' lives. The story "Wild Things I—Ghosts" addresses the concept of wholeness on a meta-level. Jones recounts how the girl whom he is holding captive—or safeguarding, as he perceives it—reminds him of a clam shell he found on the beach in his boyhood: "It was beautiful and so fragile, and he was overcome by a desire to rescue it, to keep it whole. It seemed to him then that the world conspired against such things, that the way things were was more about brokenness." Colbert gives us a collection of beautiful, haunting stories that, while stylistically fragmented, are ultimately pieced together by an omniscient hand to create the larger, unified story of a town overrun by loss and despair. The common thread occupying each of these stories is the town near the Susquehanna River, where people are wealthy in tribulations and not in capital. As we see across the stories, while the characters deal with very personal and deeply distressing issues—like faulty or failing relationships, vanished or lackluster jobs, meth addiction, and loss—these are issues that unite rather than divide. And yet, despite the deep suffering of these characters, they never experience overwhelming hopelessness. They yearn for something greater, typically sought after in nature, that gives them hope for a better future. Colbert writes affectionately about nature. Whether she's describing "two little fawns… bumping into each other…those spindly legs all akimbo…rubbing their soft little heads against his pant-legs" or describing the weightlessness of birds, where, "on our frosty fall mornings before the hummingbirds leave for the southern sunshine you can pick one up—the cold makes them sluggish—and it'll warm in your hand then whoosh, off it goes," there is a sanctity to the natural world to which her narrators all bear witness. In describing the wild in this manner, Colbert creates fleeting scenes where time slows and, for that moment, an...

Geology and geochemistry of Late Quaternary volcanism in northern Harrat Rahat, Kingdom of Saudi Arabia: implications for eruption dynamics, regional stratigraphy and magma evolution

Abstract Harrat Rahat (&lt;10 Ma) is one of the largest volcanic fields on western Arabia. In the north of the field, some of the youngest volcanic centres evolved through either point-like, complex or multiple aligned vents (i.e. along fissures), and have pyroclastic cones, lapilli fall deposits and/or lava flows associated with them. The products reflect dominantly Hawaiian eruptions, and only one centre experienced phreatomagmatism. Results from new 3 He surface-exposure dating provide constraints on stratigraphy of the youngest (&lt;0.3 Ma) products. The rocks are compositionally alkali-basalt and hawaiite, with intra-plate basalt (prevalent mantle (PREMA)) affinity. Each eruption displays a distinct whole-rock composition in an overall linear trend. We suggest that the magma source for each centre is similar, and that composition of the products is different due to different degrees of fractionation. In a single eruption, the magma that reaches the surface first is the least evolved, with the most evolved magma erupting last. We also found that the most primitive magmas erupt less explosively. We think that the degree of magma evolution might correlate with ascent times, assuming that the more evolved magma spent more time en route. We suggest that magma ascent time is likely to be longer than that of other more primitive intra-plate basalts. Supplementary material: Whole-rock chemistry results, mineral chemistry results and fractional crystallization modeling data are available at https://doi.org/10.6084/m9.figshare.c.3488988

A large refined catalog of earthquake relocations and focal mechanisms for the Island of Hawai'i and its seismotectonic implications

AbstractWe present high‐quality focal mechanisms based on a refined earthquake location catalog for the Island of Hawai'i, focusing on Mauna Loa and Kīlauea volcanoes. The relocation catalog is based on first‐arrival times and waveform data of both compressional and shear waves for about 180,000 events on and near the Island of Hawai'i between 1986 and 2009 recorded by the seismic stations at the Hawaiian Volcano Observatory. We relocate all the earthquakes by applying ray tracing through an existing three‐dimensional velocity model, similar event cluster analysis, and a differential‐time relocation method. The resulting location catalog represents an expansion of previous relocation studies, covering a longer time period and consisting of more events with well‐constrained absolute locations. The focal mechanisms are obtained based on the compressional‐wave first‐motion polarities and compressional‐to‐shear wave amplitude ratios by applying the HASH program to the waveform cross correlation relocated earthquakes. Overall, the good‐quality (defined by the HASH parameters) focal solutions are dominated by normal faulting in our study area, especially in the active Ka'ōiki and Hīlea seismic zones. Kīlauea caldera is characterized by a mixture of approximately equal numbers of normal, strike‐slip, and reverse faults, whereas its south flank has slightly fewer strike‐slip events. Our relocation and focal mechanism results will be useful for mapping the seismic stress and strain fields and for understanding the seismic‐volcanic‐tectonic relationships within the magmatic systems.

The geochemical components that distinguish Loa- and Kea-trend Hawaiian shield lavas

Recent (<5Ma) Hawaiian volcanoes define two sub-parallel spatial trends, Loa and Kea. Despite the short distance (∼30km) between adjacent volcanoes on these trends, most of the Loa-trend shield lavas are geochemically distinct from most of the Kea-trend shield lavas. These geochemical differences arise from small amounts of the LOA component in the source of Loa-trend shield lavas. This component is most prominent in the uppermost shield lavas of Koolau, Lanai and Kahoolawe volcanoes. Correlations between abundance ratios of incompatible elements and isotopic ratios of Sr, Nd, Hf and Pb in Hawaiian shield lavas indicate that the LOA component consists of three geochemically distinct materials formed by diverse processes. A gabbroic adcumulate (i.e. no trapped melt) with abundant cumulus plagioclase is responsible for the high Sr/Nd, La/Th and La/Nb in Loa-trend shield lavas relative to Kea-trend shield lavas. Also it has relatively low 206Pb/204Pb and high 208Pb/204Pb at a given 206Pb/204Pb, consistent with the low U/Pb and Th/Pb that are characteristic of plagioclase; these distinctive Pb isotope ratios require a long-time interval, ∼3Ga, to develop. This material is most abundant in the uppermost shield lavas of Koolau volcano. Possible origins of adcumulate gabbros with abundant cumulus plagioclase are the lower oceanic and continental crust. A second material in the LOA component is distinctive because it is offset from the linear trend of 176Hf/177Hf versus 143Nd/144Nd, known as the terrestrial array, to high 176Hf/177Hf at low 143Nd/144Nd. This offset requires an ancient material with high Lu/Hf. It is equally abundant in the shield lavas at Koolau, Lanai and Kahoolawe volcanoes. Possible origins of this material are ancient pelagic sediment or ancient depleted lithosphere. A third material in the LOA component is characterized by relatively high 87Sr/86Sr, but the Rb/Sr of this material is too low to explain the high 87Sr/86Sr in 4.5Ga. A relatively recent (<1Ga) event must have lowered the Rb/Sr. This material is most abundant in the shield lavas of Kahoolawe volcano.

Discovery of a trachyte ignimbrite sequence at Hualālai, Hawaii

Ignimbrites are common in many intraplate ocean islands but have been missing from the known geological record in Hawaii. During a recent field campaign, the remnants of a trachytic ignimbrite sequence have been discovered at Hualālai volcano, fortuitously preserved from subsequent basaltic lava flow cover. We provide a preliminary description of these deposits, as well as bulk and glass chemical analyses to determine their potential relationship with other nearby trachytes from Pu’u Wa’awa’a (PWW) and Pu’u Anahulu (PA). The results suggest that these ignimbrites are from neither PWW nor PA, but instead may relate to trachytes that are found as maar wallrock blocks some 20 km distant. Therefore, despite being rare overall in Hawaii, the ignimbrites—and more generally trachytes—were probably widespread around Hualālai. Compared to other intraplate ocean islands, the combination of a fast-moving plate, high magma supply, and eruption rates underneath Hawaiian volcanoes may explain the scarcity of ignimbrites preserved at the surface. Their presence at Hualālai could reflect unusual conditions of edifice stress during the transition from shield to post-shield volcanism.

Pele's Search for Home: Images of the Feminine Self

Pele, the Hawaiian volcano goddess, guided by the fire in her fire stick (Pāoa), traveled to Hawaii, creating the islands from her molten lava flow. Dr. Bray retells her rendition of this journey myth and interprets it from the perspective of the Hawaiian culture and from a matristic (ancient goddess culture) viewpoint. She adds a third perspective—a Jungian psychological view—to her interpretation. In the Hawaiian culture, Pele is the creator of the islands, and seen within the context of a matristic culture, Pele reflects the functions of the goddess of death and regeneration. Psychologically, Pele embodies difficult emotions that arise in the analytic temenos—anger, rage, hate, jealousy, envy, desire, and passion. Pele's fire creates matter; in the consulting room her fire ignites affective states of consciousness, creating the potential for psychological growth, individuation.

Automated tracking of lava lake level using thermal images at Kīlauea Volcano, Hawai’i

Tracking the level of the lava lake in Halema‘uma‘u Crater, at the summit of Kīlauea Volcano, Hawai’i, is an essential part of monitoring the ongoing eruption and forecasting potentially hazardous changes in activity. We describe a simple automated image processing routine that analyzes continuously-acquired thermal images of the lava lake and measures lava level. The method uses three image segmentation approaches, based on edge detection, short-term change analysis, and composite temperature thresholding, to identify and track the lake margin in the images. These relative measurements from the images are periodically calibrated with laser rangefinder measurements to produce real-time estimates of lake elevation. Continuous, automated tracking of the lava level has been an important tool used by the U.S. Geological Survey’s Hawaiian Volcano Observatory since 2012 in real-time operational monitoring of the volcano and its hazard potential.

Local earthquake tomography with the inclusion of full topography and its application to Kīlauea volcano, Hawai'i

We develop a new three-dimensional local earthquake tomography algorithm with the inclusion of full topography (LETFT). We present both synthetic and real data tests based on the P- and S-wave arrival time data for Kīlauea volcano in Hawai'i. A total of 33,768 events with 515,711 P-picks and 272,217 S-picks recorded by 35 stations at the Hawaiian Volcano Observatory are used in these tests. The comparison between the new and traditional methods based on the synthetic test shows that our new algorithm significantly improves the accuracy of the velocity model, especially at shallow depths. In the real data application, the P- and S-wave velocity models of Kīlauea show several intriguing features. We observe discontinuous high Vp (>7.0km/s) and Vs (>3.9km/s) zones at 5–14km depth below Kīlauea caldera, its East Rift Zone (ERZ) and the Southwest Rift Zone, which may represent consolidated intrusive gabbro-ultramafic cumulates. At Kīlauea caldera, Vp and Vs decrease from ~3.9km/s and ~2.6km/s from the surface to ~3.7km/s and ~2.3km/s at 2km depth. We resolve a high Vp zone (>7.0km/s) at 5–14km depth and high Vs zone (>3.9km/s) at 5–11km depth. This high Vp and Vs zone extends to the north of the ERZ at 5–10km depth and to the upper ERZ at 8–12km depth. In the Hilina Fault System, there is a high Vp layer (~7.0km/s) at 4–6km depth and a low Vp body of ~5.7km/s at 6–11km depth. The high Vp layer could be associated with the intrusive ultramafic gabbro sills. The velocity contrast on the north and south sides of the Koa'e Fault System indicates that the intrusive activities mainly occur to the north of the fault. Our new LETFT method performs well in both the synthetic and real data tests and we expect that it will reveal more robust velocity structures in areas with larger topographic variations.