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Research about Hawaii

Source-linked reports with geographic coverage including Hawaii.

At least 73 records · Page 4Linked to original sources
USGS2025

Alternating movement strategies of a tropical raptor

The majority of raptor species reside in the tropics, yet very little is known about their movement ecology. However, quantifying movement behavior can provide otherwise elusive information on resource needs, habitat selection, and ecological constraints, which is important for understanding ecological patterns and the management of species of conservation concern. On the Island of Hawai‘i, Hawai‘i, USA, the endemic ‘Io, or Hawaiian Hawk ( Buteo solitarius ), is a species of conservation concern that little is known of their movement ecology, yet they are dependent on a fragmented and rapidly changing environment. We tracked 15 individuals for up to 18 months across a diverse landscape on the eastern side of the island. We found that all ‘Io occupied a relatively small geographic area, their place of residency, where they spent all or most of their time. However, 10 individuals also exhibited an alternative movement pattern, where individuals repeatedly commuted back and forth between their place of residency to another, geographically disjunct location. These commuter periods, which could last from 24–180 days, were characterized by frequent (9–259) movements, with individual trips lasting 4–77 h away from their place of residency and 12–47 h in between commuter trips. In most cases, individuals went to the same non-contiguous commuting destination, even across multiple commuting sessions, indicating high fidelity to commuting locations. The ‘Io is a forest adapted Buteo but occurs across a diverse landscape from forest to agriculture lands to urban areas. Habitat selection analysis indicated high individual variation among different birds, but generally a preference for forest patches at localized levels. The discovery of the alternative commuting strategy for many ‘Io represents a cryptic movement pattern in the species, demonstrating the power of small, long-lived Global Position System tracking devices to track movement and providing important insights into the ecology of a tropical island raptor.

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USGS2025

Temporal associations between ambrosia beetles and ʻōhiʻa (Metrosideros polymorpha) artificially inoculated with Ceratocystis lukuohia

Wood boring ambrosia beetles play a central role in the spread of Ceratocystis wilt of ‘ōhi‘a, a fungal disease caused by Ceratocystis lukuohia that kills the bioculturally important ‘ōhiʻa ( Metrosideros polymorpha ) tree. Beetles contribute to the spread of the disease by extruding fungus-infected wood particles (frass). Disease mitigation can benefit from knowledge of ambrosia beetle life-history and fungal survival in affected ‘ōhi‘a. We investigated temporal associations among tree death, the timing and duration of beetle attacks, and the persistence of viable C. lukuohia within intentionally infected (inoculated) ʻōhiʻa at three sites that approximate the elevational range of the disease on the Island of Hawaiʻi. Beetles most frequently attacked inoculated trees at the time when foliage first showed symptoms of infection (yellow leaves; n = 9) although some attacks were observed during earlier (green leaf; n = 3) and later (brown leaf; n = 3) stages of symptom progression. On average, beetles initiated new attacks for nearly one year after trees were inoculated. We tracked active galleries of Xyleborinus saxesenii , Xyleborus ferrugineus and Xyleborus simillimus and found they produced frass with viable C. lukuohia propagules for 122.8 ± 40.0, 275.8 ± 32.7 and 304.2 ± 53.4 days, respectively. Infected ʻōhiʻa felled from our mid-elevation site at the end of the study revealed viable fungal propagules and the presence of X. ferrugineus over two years after trees first appeared symptomatic of infection, suggesting that Ceratocystis wilt of ʻōhiʻa remains a threat to spread from infected trees long after trees succumb to the disease.

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USGS2025

The structural and functional impacts of invasive Psidium cattleianum in forests on the Island of Hawai’i

During the past century, the proliferation of invasive species has contributed to loss of biodiversity and ecosystem degradation. In forests, invasive tree species can alter ecosystem function, but the underlying mechanisms of these changes are not fully understood. We use the ongoing invasion of P. cattleianum on the Island of Hawai’i to test the hypotheses that invasive structural changes drive changes to forest evapotranspiration (ET). The aim of our study is first to quantify the structural changes to native ‘ōhi‘a -dominated forest impacted by a gradient of P. cattleianum invasion. Our results suggest that invasive P. cattleianum causes significant changes to the vegetation density and structure of native forest on the Island of Hawai’i, including increased vegetation area index, decreased mean leaf height, and decreased structural heterogeneity. Second, we strove to understand the functional implications of structural changes through a biophysical modeling simulation, testing the sensitivity of ET to canopy structure under contrasting scenarios. Modeling the functional impact of structural change, we found that plots with P. cattleianum invasion importance value (IV inv ) above 0.35 have a higher likelihood to increase ET compared to plots with P. cattleianum invasion less than 0.35 IV inv . Modeled increases in ET due to invasion ranged from 19 and 123% relative to native transects. The large variation in ET increases is caused by structural variation because the modeling scenarios did not include potential species differences in leaf physiology. Diagnostic scenario modeling shows the effect size of increased leaf area on modeled ET is constrained by the structural arrangement, that is vertical distribution, of the increased vegetation. Thus, invasion structure that increases vegetation density in taller, more sunlit forest strata will lead to a greater increase in ET compared to invasion structure that increases vegetation density in the shaded forest understory. Overall, we conclude the vertical distribution of vegetation is an important factor shaping the impact of invasive P. cattleianum on the forest water balance.

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USGS2025

Disease-driven collapse of the native Kauaʻi avifauna and the rise of introduced bird species

Hawaii hosts one of Earth’s most unique and threatened avifaunas. Upslope migration of mosquito-vectored avian malaria on Kauaʻi (maximum elevation 1,598 m) has likely caused its rapid loss of avifaunal diversity; only 8 of 13 historic forest bird species remain. We update the status and trends of Kauaʻi forest bird populations since the original (1981) surveys using the latest (2023) survey data and distance sampling. We fit detection functions to species-specific count data and stratified estimates across the Interior (since 1981) and Exterior (since 2000) survey areas, and between low (900–1,100 m), medium (1,100–1,300 m) and high (> 1,300 m) elevation bands (since 2000). Log-linear trends of ʻakekeʻe ( Loxops caeruleirostris ), ʻanianiau ( Magumma parva ), ʻiʻiwi ( Drepanis coccinea ), and Kauaʻi ʻamakihi ( Chlorodrepanis stejnegeri ) steeply declined across the timeseries, with extinction of ʻakekeʻe and ʻiʻiwi expected before 2050. Undetected in 2023, ʻakikiki ( Oreomystis bairdi ) were excluded from analysis. ʻApapane ( Himatione sanguinea ), Kauaʻi ʻelepaio ( Chasiempis sclateri ), Chinese hwamei ( Garrulax canorus ), and white-rumped shama ( Copsychus malabaricus ) were stable overall. Northern cardinal ( Cardinalis cardinalis ) steadily declined, whereas Japanese bush warbler ( Horornis diphone ) and warbling white-eye ( Zosterops japonicus ) exponentially increased. Taxonomic and functional diversity did not vary greatly across our timeseries, while the proportion of introduced species in the Exterior increased from 34 to 59%. However, introduced species do not replace the losses of ecological functions from native species, whose populations are likely declining from avian malaria. Future monitoring can be used to evaluate forest bird population responses to mosquito suppression using the Incompatible Insect Technique.

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USGS2025

Ten more years of the golden pheasant (Chrysolophus pictus) on Maui, Hawaiian Islands

Since the introduction of the Golden Pheasant ( Chrysolophus pictus ) to Haleakalā volcano, Maui, three decades ago, subsequent reports have hinted at an expansion of this nascent population. We draw from a variety of data sources to learn about this pheasant's present status on Maui. First, forest bird surveys conducted every five years revealed that the frequency of Golden Pheasant detections has greatly increased, and the bird has both maintained its former distribution and expanded eastward into Haleakalā National Park (NP). Second, reports to eBird from The Nature Conservancy's Waikamoi Preserve, where Golden Pheasants first appeared on Maui, demonstrate that the frequency of observations has increased and is strongly seasonal, predominantly in the spring. Third, autonomous recording units monitoring endangered forest birds recorded pheasants too, adding new locations. Finally, trail cameras set to monitor mammals picked up pheasants as well, showing males of two color morphs: original “wild-type” and “dark-throated.” Trail cameras also documented a small juvenile at Waikamoi Preserve and both females and males in Haleakalā NP. By “connecting the dots” of mapped occurrences, we traced the pheasant's progression through a narrow band of subalpine cloud forest with open understory, extending from Waikamoi Preserve eastward to upper Kīpahulu Valley, a distance of 14 km. In summary, this body of evidence supports the claim that the Golden Pheasant has established a self-sustaining population on Maui, and we propose that the species' success there may be attributed to the minimal influence of predators and the absence of competing gallinaceous birds in its preferred habitat.

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USGS2025

Sensitivity study for the continuous gravimetric network of the Kīlauea Volcano in Hawaii: First results

We present a sensitivity analysis for the continuous gravimetric monitoring network at Kīlauea volcano, Hawaiʻi, USA. Our methodology is an extension of the method proposed by Fernández et al. (1999) and enables the estimation of the intrusion radius-depth range where the effects (surface gravity changes in our case) would be clearly detected. The magmatic intrusion is considered as a spherical point source, and we use the elastic-gravitational deformation model proposed by Rundle (1982) and extended by Rundle and co-workers (Fernández and Rundle 1994a; 1994b; Fernández et al. 1997; 2006). Additionally, a correction for topographic effects is included. We obtain first results indicating that, in the case of Kīlauea, a network configuration using five gravimeters at radial distances between 0.5 and 3 km from the surface projection of the Halemaʻumaʻu source centre could be an effective strategy for volcano monitoring, facilitating the early detection of gravity effects produced by magmatic intrusions with a radius a, occurring at depths between 3 and 30 km.

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USGS2025

Onset and evolution of summit lava fountaining during the Mauna Loa 2022 eruption

The start of the Mauna Loa 2022 eruption in the Mokuʻāweoweo summit caldera was entirely captured through webcam videos. We analyzed footage from the ~ 7-h summit episode, processing > 87,000 frames using a newly automated method to measure fountain heights, fissure lengths, and inflight ejecta volumes. The summit episode comprised four phases. In Phase 1 (~ 1 h ), a ~ 1 km long fissure propagated from southwest to northeast, with steady fountain heights reaching 125 m. In Phase 2 (~ 50 min ), two further fissure segments extended the total length to ~ 2.4 km, with fountains focused into point sources reaching up to 70 m. In Phase 3 (~ 70 min ), the eruption was steady with no major changes in eruptive behavior. In Phase 4 (~ 4 h ), fountains became unsteady and weak (< 30 m). Fissure growth rates varied from ~ 20 to -9 m/min, and bulk magma flux peaked at 2.7 × 10 4 m 3 /s. An inverse relationship between maximum fountain heights and fissure lengths suggests that total magma flux was nearly constant until Phase 4. We propose an interconnected feeding system for the summit episode with a preferential pathway for gas-rich magma in the southwest portion of the caldera. The sustained nature of the episode was likely driven by the fast rise of melt coupled with small bubbles, with trains of decoupled larger bubbles producing pulsations. Webcam videography was an effective tool to quantify early-stage eruption parameters and could be further explored for rapid response and fine-tuning of hazard mitigation strategies on erupting basaltic volcanoes.

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USGS2025

Rapid emplacement of the Keaiwa Lava Flow of 1823 from the Great Crack in the Southwest Rift Zone of Kilauea volcano

The Keaīwa Lava Flow of 1823 in the Southwest Rift Zone of Kīlauea volcano is unusual for its expansive pāhoehoe sheet flow morphology and lack of constructive vent topography, despite having a similar tholeiitic basalt composition to other lavas erupted from Kīlauea. This lava flow issued from a ∼10-km-long continuous fissure now known as the Great Crack, and has an unusually thin sheet flow morphology with margin thicknesses of ∼15–110 cm (average of 42 cm). Based on field observations of the lava flow at its fissure vent (e.g., drain-back features), we propose that the Great Crack formed, or at least significantly widened, just prior to and syn-eruptively with this 1823 eruption. The absence of pyroclastic cones or spatter ramparts indicates that the eruption consisted of a rapid outpouring of relatively degassed lava as the fissure unzipped. The rapidly moving lava flow overtopped pre-existing tumuli and scoria cones (e.g., Lava Plastered Cones) up to ∼10 m tall. Glass and whole-rock chemistry yield homogeneous compositions for the lavas erupted from the Great Crack, with glass compositions of 6.40 ± 0.10 wt% MgO and whole-rock compositions of 7.39 ± 0.07 wt% MgO. Lava pads erupted from a short western fissure system are richer in mafic minerals (e.g., olivine and clinopyroxene), and show slightly more MgO-rich whole-rock compositions (7.79 ± 0.05 wt%). MgO-in-glass thermometry on juvenile spatter yield eruption temperatures of 1153 ± 13°C that are typical of Kīlauea lavas. Thus, the extensive sheet-like lava flow morphology is not a direct consequence of unusual magmatic or rheological conditions (i.e., low viscosity). Instead, the flow morphology is associated with high effusion rates caused by sudden drainage of uprift magma as it erupted from the Great Crack. Lava flow modeling on a 2-m-resolution digital elevation model indicates that a minimum bulk effusion rate of ∼5800 m 3 /s (∼3500 m 3 /s dense rock equivalent) and a minimum flow velocity of ∼11 m/s are required for the lava flow to overcome the topography of the Lava Plastered Cones. This effusion rate is among the highest inferred for eruptions in Hawaiʻi and around the world. This study highlights a less frequent eruption style at Hawaiian volcanoes characterized by a sudden outpouring of lava from an unusual fissure system. Local eyewitness accounts indicate that the 1823 eruption was preceded by seismicity. Given the complex magmatic-volcanic-tectonic relations across Kīlauea, we speculate that the south flank could have slipped over one or more events that ultimately triggered unzipping of the Great Crack and passive release of briefly stored uprift magma. An eruption similar to 1823 at Kīlauea or Mauna Loa, with an eruptive timeframe that could be as short as an hour, with high effusion rates and rapid flow front velocities, would not easily allow for a timely response.

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USGS2025

Crustal structure along and surrounding the Hawaiian Islands: Volcanic island construction across scarred oceanic crust

The Hawaiian Ridge is a classic example of an intraplate volcanic island chain emplaced on oceanic lithosphere. We seek to constrain both the deformation from island loading around the Hawaiian Ridge and the influence of the oceanic lithosphere, including the Molokaʻi fracture zone (MFZ), on off-axis volcanic emplacement. To examine these processes, we conducted a marine geophysical experiment in 2018 that included the acquisition of eight multichannel seismic reflection lines and used a 6,600 in 3 tuned air gun array and an ultra-long hydrophone streamer cable towed behind R/V Marcus G. Langseth across and around the southern Hawaiian Ridge. We image both the top of igneous oceanic crust and the Moho, and we observe significant variations in regional crustal structure and thickness variations, Moho characteristics, the locations of the buried MFZ, and the flexure of the Pacific oceanic lithosphere under the Hawaiian Ridge. We observe up to ∼4.5 km of deflection of the igneous oceanic crust in response to the volcanic load with sediment thickness increasing to ∼3–3.4 km near the ridge but not correlating with the deflection. A systematic difference in igneous oceanic crustal thickness is found north (average ∼5.2 km) and south (average ∼5.9 km), of the MFZ that also correspond to changes in Moho characteristics. The MFZ itself is associated with the largest crustal thickness variations (∼3.7–7.6 km). Magma ascent through these different crustal regions may account for some variations of magmatic flux to the surface along the Hawaiian Ridge.

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USGS2025

Status and trends of forest bird populations at Hakalau Forest National Wildlife Refuge, 1987–2024

Since 1985, the Hakalau Forest Unit of the Big Island National Wildlife Refuge Complex (hereafter, Hakalau) has protected the largest endemic forest bird diversity in the State of Hawaii. This includes three endangered and one threatened species and their habitats. Hakalau’s vast area (155 km2), mostly high elevation (>1500 m) montane forest, provides refuge from avian malaria (Plasmodium relictum) vectored by introduced southern house mosquitoes (Culex quinquefasciatus). However, increases in the seasonal temperatures optimal for disease carrying mosquitoes associated with climate change have coincided with recent downward trends of native species in the closed forest area of the refuge (1450–1750 m), where disease is most likely to occur. Therefore, to inform refuge management with the most updated information on these populations and their trends, we analyzed forest bird survey data collected using point transect distance sampling with new survey data from 2021–2024. We stratified our analysis across management units, including the open forest and pasture since 1987, and the closed forest since 1999, and across four elevation ranges (<1500, 1500–1700, 1700–1900, and >1900 m) since 1999. We used distance sampling to estimate species- and strata-specific abundances and applied log-linear regression to detect trends across the timeseries. We found a continuation of previous trends, wherein most native forest birds declined in the closed forest strata (mostly below 1700 m) and increased in the highest elevation and pasture strata. Patterns were highly species-specific for the three lower elevations and open forest strata. ‘Apapane (Himatione sanguinea) and warbling white-eye (Zosterops japonicus), the most abundant native and introduced bird species, respectively, increased in nearly all strata. ‘I‘iwi (Drepanis coccinea) and Hawai‘i ‘amakihi (Chlorodrepanis virens virens), also common, decreased in closed forest, were stable in open forest, and increased in pasture. Both species were generally stable or increasing across all elevation bands, except Hawaiʻi ʻamakihi decreased in the below 1500 m and the 1500–1700 m elevation bands. All three of the federally endangered forest bird species declined in closed forest. Hawai‘i ‘ākepa (Loxops coccineus) also declined in the open forest and 1700–1900 m band and was the only species to decline overall. ‘Akiapōlā‘au (Hemignathus wilsoni) declined in closed forest but increased overall. ‘Alawī (Loxops mana, also known as Hawai‘i creeper) also decreased in the closed forest, but was stable to increasing in most strata and remained stable overall. Hawaiʻi ʻelepaio (Chasiempis sandwichensis) declined in closed forest, was stable in open forest and most elevation strata, and increased in pasture. ʻŌmaʻo (Myadestes obscurus) was stable in open and closed forest and at middle elevations and increased in the pasture. Introduced red-billedleiothrix (Leiothrix lutea) declined in closed forest, was stable in the open forest and at most elevations, and increased in the pasture. Coinciding with these changes, seasonal conditions for vector occurrence have continued to lengthen in the lower elevation strata through 2024, while Hakalau’s outplanting efforts continued to increase forest cover in the pasture, suggesting that disease-free habitat may have decreased in the closed forest and increased in the pasture. The declines in the closed forest and mixture of trends in the open forest and middle elevations bands suggest emigration into the higher elevation strata from lower elevation strata, and that possible threats have suppressed forest birds even at elevations >1500 m.

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USGS2025

Fine-grained temporal population monitoring of a declining, critically endangered Hawaiian honeycreeper

Annual point counts are commonly used to monitor birds to track population densities across space and time. Palila ( Loxioides bailleui ) are surveyed annually in the first quarter, but we recently instituted quarterly sampling that offers a unique opportunity to improve estimator precision. We conducted point-transect distance sampling point counts during the first quarter of 2020 through 2024, and the second through fourth quarters in 2022 and 2023, and the second quarter in 2024. The reduced sampling intensity during the quarterly counts, however, requires model-based methods to estimate abundance to the entire sampling frame. We modeled spatial and temporal correlation using a soap film smoother within a generalized additive modeling framework, a density surface model, fitted to palila counts each quarter for the five-year timeseries to track changes in population abundances. Our results indicate that palila maintained a high-density hotspot throughout the five-year timeseries; however, the extent of the hotspot declined substantially over the timeseries while densities within the hotspot declined from about 3 birds/ha in 2020 to about 1 bird/ha in 2024, which resulted in a 66% decline in palila abundances over 5 years. Density surface model estimates give on average a confidence interval width that was 74.7% shorter than the associated distance sampling confidence interval widths. Our results indicate that palila may benefit most if management actions were applied within the remaining hotspot. Additionally, this temporally fine-grained sampling provides information on seasonal movement patterns and resource tracking, and population response to management and conservation actions. Our spatially explicit, model-based approach is applicable to a wide range of monitoring programs, particularly those with inconsistent, opportunistic spatial coverage.

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USGS2025

Pacific island landbird monitoring report, Kalaupapa National Historical Park, 2021

In 2021, landbird surveys were conducted at Kalaupapa National Historical Park on the island of Molokaʻi to assess changes in species composition, distribution, and population densities since 2005. Point-transect distance sampling surveys were conducted on six transects at 50 landbird monitoring stations within an 1,834-hectare area. A total of nine landbird species were detected, with the ʻApapane ( Himatione sanguinea ) the only endemic Hawaiian species detected. Sufficient detections of six species allowed for population density and abundance estimates, which were compared to 2005 estimates using a two-sample z-test. The abundance of ʻApapane declined by 57% to 2,476 ± 729 (SE) birds in 2021 compared to 2005. Population densities of the House Finch ( Haemorhous mexicanus ), Japanese Bush Warbler ( Horornis diphone ), Warbling White-eye ( Zosterops japonicus ), and White-rumped Shama ( Copsychus malabaricus ) were also lower in 2021 than in 2005, but comparisons were inconclusive. Since 2005, the Red-billed Leiothrix ( Leiothrix lutea ) irrupted within the survey area to an estimated abundance of 11,088 ± 1,208 birds. The Warbling White-eye was the most abundant species, with an estimated 101,724 ± 11,692 birds. Surveyors failed to detect the Hawaiʻi ʻAmakihi ( Chlorodrepanis virens ), which has become increasingly rare on Molokaʻi. The federally threatened ʻIʻiwi ( Drepanis coccinea ) was last seen on Molokaʻi in 2010, further raising concerns about its potential extirpation. The Olomaʻo ( Myadestes lanaiensis ), an endemic thrush, has not been detected since 1980 and is likely extinct. These findings show the ongoing shift toward non-native bird communities and highlight the challenges of conserving native forest birds amidst widespread avian malaria transmission, introduced predators, and extensive habitat degradation.

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USGS2025

Photographic guide to the leaf litter arthropod community of the lowland wet forest ecosystem of the Island of Hawaiʻi

Leaf litter arthropods are important components of the food web in forests, and their presence and diversity can provide information on forest health. There has been very little documentation of the leaf litter arthropods in Hawaiian forest ecosystems. This technical report is a photographic guide to some common arthropods collected from forest leaf litter at the Liko Nā Pilina Hybrid Ecosystems Project study site, a lowland wet forest in Hilo, Island of Hawaiʻi, USA. Leaf litter samples were collected from plots of invaded and experimental restoration communities using two complementary methods (litterbags and quadrats), and arthropods were extracted using Berlese funnels. The field site contained many morphospecies that were rare and locally distributed across plots, and only a few that were very common and widely distributed. The majority of the morphospecies identified were mites. This photoguide is designed to help identify arthropods found in plant litter in Hawaiian lowland forests and it may assist with research and education efforts concerned with the diversity, ecology, or conservation of litter arthropods across the Hawaiian archipelago and other Pacific islands.

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USGS2025

Crustal to mantle melt storage during the evolution of Hawaiian volcanoes

As the Pacific Plate migrates over the mantle plume below Hawaiʻi, magma flux decreases, resulting in changes in eruptive volume, style, and composition. It is thought that melt storage becomes deeper and ephemeral with the transition from highly voluminous tholeiitic (shield stage) to the less voluminous alkaline (post-shield and rejuvenation stages) magmatism. To quantitatively test this, we applied high-precision fluid inclusion barometry via Raman spectroscopy to samples from representative volcanoes of different evolutionary stages. This suggests an evolution from shield-stage shallow magma storage (~1 to 2 kilometers) for Kīlauea to a post-shield stage that includes crustal magma storage within the volcanic edifice (~2 kilometers) and deeper storage below the Moho (~20 to 27 kilometers) for Haleakalā. The rejuvenation stage (Diamond Head) displays mantle-dominated storage (~22 to 30 kilometers). High melt fluxes likely form stable conduits from the mantle to a shallow reservoir in the shield volcanoes. As melt flux decreases, the Moho becomes the boundary controlling melt stagnation and evolution.

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USGS2025

Social sensing a volcanic eruption: Application to Kīlauea, 2018

Protecting lives and livelihoods during volcanic eruptions is the key challenge in volcanology, conducted primarily by volcano monitoring and emergency management organisations, but it is complicated by scarce knowledge of how communities respond in times of crisis. Social sensing is a rapidly developing practice that can be adapted for volcanology. Here we use social sensing of Twitter (currently known as X) posts to track changes in social action and reaction throughout the 2018 eruption of Kīlauea on the island of Hawai`i. The volume of relevant posts very rapidly increases in early May, coincident with the beginning of the eruption; automated sentiment analysis shows a simultaneous shift towards more negative emotions being expressed in post text. Substantial negative trends in sentiment are evident in reaction to high-impact events, including the destruction of a popular residential area and injuries sustained by tourists viewing the eruption. Topics of local Twitter conversation reveal societal actions, including the sharing of hazard warnings, mitigation actions, and aid announcements. Temporal trends in societal actions reflect patterns in volcanic activity (e.g. the peak and waning of eruptive activity), civil protection actions (e.g. risk mitigation actions and the communication of official warnings), and socioeconomic pressures (e.g. the destruction of homes). Local tweets detailing eruption damage and disruption display a similar temporal trend to independent estimates of the number of buildings in contact with lava. We show how hazard and risk information is discussed and reacted to on Twitter, which helps inform our understanding of community response actions and aids situational awareness, and outline how our approach could be adapted for use in real time.

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USGS2025

Rhenium-osmium and oxygen isotope homogeneity during the 2022 Mauna Loa eruption and implications for basaltic magma storage

Mauna Loa is one of the largest and most active volcanoes on Earth. The most recent eruption of Mauna Loa started on 27 November 2022, lasted for 13 days, and was preceded by the longest repose time of 38 years in its modern history. In this contribution, new trace- and highly siderophile-element (HSE: Os, Ir, Ru, Pt, Pd, Re) abundances, 187 Re- 187 Os, and 18 O/ 16 O data are reported for the 2022 lavas. These lavas have a limited range of MgO (6.2 ± 0.1 wt.%) and Ni (83 ± 2 µg/g), with a broader range of Re (0.3 to 1.3 ng/g) and consistent Os (0.031 to 0.080 ng/g) contents. They have 187 Os/ 188 Os ratios (0.1345 to 0.1385) which are, on average, more radiogenic than Mauna Loa picrites (0.1331 to 0.1349) and are similar in composition to more differentiated Mauna Loa tholeiite lavas (0.1340 to 0.1381). The oxygen isotope compositions of glassy samples are 5.35 ± 0.15‰ ( n = 13) and span a range in δ 18 O of + 5.0 to + 5.5‰, with an average composition 0.2 to 0.3‰ lower than MORB. The δD value is − 81 ± 11‰ ( n = 5) at very low (0.03 ± 0.015 wt.%) H 2 O concentrations. The 2022 Mauna Loa eruption is similar in terms of δ 18 O but contrasts in terms of 187 Os/ 188 Os variability, with the recent longer-lived eruptions on La Palma (Canary Islands; 85 days) in 2021 and on the Reykjanes Peninsula (Iceland) that began in 2021 and are still ongoing. Initial lavas were more fractionated for both the Canary Islands and Iceland eruptions, producing more radiogenic Os isotope compositions than later erupted products. The 2022 Mauna Loa eruption showed no such trends. The limited range in isotope compositions of the 2022 Mauna Loa lavas and their strongly fractioned HSE patterns reflect long-term storage, crystal fractionation, and assimilation of related basaltic volcanic edifice materials by the parent magma beneath the volcano prior to eruption triggering. Eruption of differentiated and homogeneous tholeiite lavas at the summit caldera and high on the volcano’s flank, with emplacement of accumulative picrites lower on the volcano, are consistent with neutral buoyancy arguments.

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USGS2025

The scientific benefits of a statewide, standardized, coastal wetland monitoring program in Hawaiʻi

In this viewpoint, we provide a scientific justification for a statewide, standardized, coastal wetland monitoring program for Hawaiʻi, USA. Hawaiian coastal wetlands provide important habitat for endangered waterbirds, invertebrates, plants, and the Hawaiian hoary bat (ʻōpeʻapeʻa; Lasiurus semotus ) as well as support Indigenous food systems. Currently, numerous agencies and groups in Hawaiʻi collect data on coastal wetlands, but information is not typically shared and methods are not standardized. A statewide, standardized, coastal wetland monitoring program with a centralized database would allow managers to keep better track of progress toward restoration goals, population changes of conservation-reliant species, outbreaks and impacts of avian botulism, rates of coastal salinization, and many other critical issues across space and time. Monitoring combined with targeted research could fill critical knowledge gaps about the types, functions, values, and biodiversity of Hawaiian coastal wetlands. Ultimately, the improved knowledge gained from long-term coastal wetland monitoring could inform landscape-scale restoration actions and adaptive management of coastal wetlands under sea-level rise and climate change.

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