Future Hazard Research Articles

Rapid karstification process with evaporite-driven sinkholes in Southern Kohat Basin, NW Pakistan

Sinkholes are small karstic features in soluble rocks that play an essential role in karstification and cause severe environmental hazards. The Karak region of the Himalaya foothills showcases one of the best exposures of karstification landforms, given their highly soluble nature and salt dissolution activities. The well-developed sinkholes are unique worldwide, yet have not been investigated. Here, we apply Interferometric Synthetic Aperture Radar (InSAR), resistivity profiles, and field observations to study the karstification process in this region. InSAR detects numerous localized subsiding zones reflecting rates up to 29 mm/year from 2014 to 2023. Resistivity profiles and field observations catalog them as cover collapse, bedrock collapse, and bedrock sagging sinkholes, carrying distinctive evaporite-driven dissolution features controlled by faulting activity. The results enhance our understanding of the linkages between sinkhole development, subsidence, and subsurface structures, emphasizing the need for comprehensive planning to mitigate future hazards in this less-representative yet populated region.

A New Mechanism of Supraventricular Tachycardia: Gene Mutation.

Supraventricular tachycardia (SVT) is very common in daily clinical practice, especially in the emergency department, with rapid onset and urgent management. The review highlights the recent genetic predispositions and mechanisms in SVT. Through analysis of epidemiology, familial clustering, and gene mutations of the relevant literature，the review elucidates the genetic properties and potential pathophysiology of SVT. There are many pathophysiological mechanisms related to atrioventricular node reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT). Currently, there is relatively little research on inappropriate sinus tachycardia (IST), atrial tachycardia (AT), and congenital junctional ectopic tachycardia (CJET). It seems that every type of SVT has gene mutations in ion channels, with three types of SVT having gene mutations in signaling pathways, and others including gene mutations in beta-adrenergic-receptor autoantibodies, autonomic nervous system, and AV node structure. SVT has certain genetic characteristics and is often associated with other heart diseases. From the analysis of mutated genes in SVT, it appears to be a type of cardiac ion channel disease. Unlike common ion channel diseases, it is more insidious and more susceptible to external factors. The confirmation of the genetic basis of SVT provides direction for future hazard stratification assessment and gene targeted therapy drug research.

Examining Intraethnic Disparities in Tornado Hazard Understanding, Reception, and Response in Latinx/e Communities in the Southeast United States

Abstract The Southeast region in the United States has a high risk for tornadoes and tornado-related losses (e.g., fatalities, injuries, damages). For the public in tornado-vulnerable areas, receiving warning information is essential for seeking protective action during a tornado event. However, for Latinx/e households in the Southeast, social, cultural, and political factors pertaining to language barriers, cultural differences, and trust in public officials often inhibit the effectiveness of warning communication strategies. The current study utilized a survey among 820 Latinx/e adults across 11 states in the U.S. Southeast. Using the Wilcoxon–Mann–Whitney (WMW) test, we examined if language, nativity, and immigration status impacted how Latinx/e populations receive, understand, and act upon severe weather information in the Southeast region. Results found intraethnic disparities related to tornado hazard understanding, reception, and response among Latinx/e adults based on language, nativity, and U.S. citizenship status. These findings suggest that NWS and its partners work with Latinx/e communities to adjust their communication strategies to consider ethnic heterogeneity in future hazard research, alert systems, and targeted outreach campaigns. Significance Statement We sought to determine if Latinx/e populations in the Southeast United States face distinct social and systematic challenges and exhibit varying levels of preparedness and awareness in the face of tornado hazards. We analyzed tornado warning comprehension, weather information sources, and barriers to protective actions among 820 Latinx/e participants, along with intraethnic disparities or vulnerabilities that may impact an individual’s or community’s ability to prepare for, respond to, and adapt to tornado hazards. These findings are important for forecasters, broadcasters, emergency managers, and others responsible for alerting the public during severe weather situations in the Southeast. Understanding differences in human vulnerability in the face of tornado threats can help inform better disaster planning and response for vulnerable and underrepresented populations.

Projecting Future Chronic Coastal Hazard Impacts, Hotspots, and Uncertainty at Regional Scale

AbstractWhile there is high certainty that chronic coastal hazards like flooding and erosion are increasing due to climate change induced sea‐level rise, there is high uncertainty surrounding the timing, intensity, and location of future hazard impacts. Assessments that quantify these aspects of future hazards are critical for adaptation planning under a changing climate and can reveal new insights into the drivers of coastal hazards. In particular, probabilistic simulations of future hazard impacts can improve these assessments by explicitly quantifying uncertainty and by better simulating dependence structures between the complex multivariate drivers of hazards. In this study, a regional‐scale probabilistic assessment of climate change induced coastal hazards is conducted for the Cascadia region (Northern Washington to Northern California), USA during the 21st century. Three co‐produced hazard proxies for beach safety, erosion, and flooding are quantified to identify areas of high hazard impacts and determine hazard uncertainty under three sea‐level rise scenarios. A novel chronic coastal hazard hotspot indicator is introduced that identifies areas that may experience significant increases in hazard impacts compared to present day conditions. We find that beaches near the California‐Oregon border and in Northern Washington have larger hazard impacts and hazard uncertainty due to their morphologic setting. Erosional hazards, relative to beach safety and coastal flooding, will increase the most in Cascadia during the 21st century under all sea‐level rise scenarios. Finally, we find that hazard uncertainty associated with wave and water level variability exceeds the uncertainty associated with sea‐level rise for most of the 21st century.

Measuring improvements in occupational health and safety in the artificial stone benchtop industry.

Workers in the stone benchtop industry in Australia are at high risk of silicosis due to exposure to respirable crystalline silica (RCS) from the dry processing of artificial stone. In Victoria, Australia, a multifaceted response including education, regulatory changes, inspection site visits, and occupational health screening programme began in 2019. We aimed to review the success of this approach to safety practices in the industry. Data were available from 2 sources: first, responses provided by workers during their occupational health screening (2019 to 2024), which included a systematic occupational history. Jobs examined included roles in the stone benchtop industry with RCS exposure and were analysed in relation to reported safety practices pre and postregulatory changes in August 2019, which prohibited unrestricted dry cutting. Second, data were obtained from the Regulator describing the numbers of visits to industry worksites and the numbers and types of compliance notices issued between 2018 and 2024. In total, 1921 jobs from 1007 workers were eligible for analysis, of which 869 were prior to the 2019 regulatory change and 557 commenced after. The proportion of workers reporting "never" dry cutting rose from 17.3% to 67.2% (P < 0.001), use of recommended ventilation and respirator increased from 26.0% to 36.5% (P < 0.001), and 44.9% to 86.5% (P < 0.001), respectively. Of the 543 worksites visited (2757 site visits in total), 352 (64.8%) received at least one compliance notice and the types of notices varied over time. Administrative controls/housekeeping and health monitoring notices were the most common in 2019 to 2021 but tools/equipment notices increased substantially in 2022 onwards. Prior to the changes, a large proportion of jobs involved unrestricted dry processing of artificial stone with inadequate protection. After the changes, practices improved although some jobs continued to involve dry processing without adequate control of dust. This multifaceted approach vastly improved safety practices in the stone benchtop industry over 5 years. These data are relevant to occupational health and safety professionals and regulators in countries where artificial stone is used and potentially for implementation of new measures in response to a new workplace hazard in future.

Quantifying Volumes of Volcanic Deposits Using Time-Averaged ASTER Digital Elevation Models

Quantifying the volume of erupted volcanic material, particularly lava flows and domes, provides critical insights into the dynamics of an eruption. This in turn aids in future hazard modeling, mitigation, and response. However, acquiring the necessary topographic datasets to calculate volumetric change is difficult, especially for active volcanoes in remote regions. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument has acquired global photogrammetric data since 2000, from which individual scene digital elevation models (DEMs) are created. We present a new straight forward method using ASTER DEMs to measure the volume of emplaced lava flows, domes, and tephra cones. We focus on five case studies that represent different eruption styles and products. For each of these we compare the results to those from previous studies that used alternative topographic datasets, such as synthetic aperture radar (SAR), airborne photogrammetry, or Light Detection and Ranging (LiDAR) measurements. These datasets, however, are expensive to acquire or lack the needed temporal resolution. We show that in nearly all cases, our volume results are either within the reported range for the eruption or ≤ 0.05 km3 of the previously reported value derived from SAR or LiDAR. The simplicity of the ASTER DEM approach combined with the global coverage of the data products enables more timely production of accurate volumetric data during and following an eruption, which can then be used to assess past and future eruption dynamics.

Envisioning the sustainable and climate resilient hospital of the future

ObjectivesThis study aims to create a vision of the future hospital to help healthcare leaders understand how changes in society and the healthcare system, compounded by climate change, could affect future hospital estate. Study designThe study is part of a larger project based on participatory backcasting aimed at providing integrated strategies for transitioning to a zero-carbon future and adapting to existing climate change through improved asset management. MethodsThe data presented in this paper were collected during a full-day workshop to construct the vision of the future hospital in 2050. A multidisciplinary team of 19 participants participated in the discussions. A six-phase thematic analysis was applied to the data to develop the narrative vision and graphic recording. ResultsThe healthcare system is undergoing transformative changes due to evolving healthcare delivery, patient expectations, emerging technologies, climate change, and sustainability. However, current hospital strategies often fail to consider the interrelationship between the hospital estate and its socio-environmental context. Policymakers, healthcare system leaders, and hospital leaders need a clear vision of the hospital of the future to implement transformational strategies. ConclusionsHealthcare transformations require shifting from traditional centralised hospitals to a more flexible, distributed model. Healthcare leaders need to proactively assess how hospitals respond to current and future hazards and consider the impacts within the context of integrated and dispersed healthcare delivery. To address this, a systematic approach to modelling hazards and evaluating design or upgrading options is essential to mitigate the transfer of climate-related risks within healthcare systems.

Expecting the expected – learning from the past to provide forward scenarios through geomorphic change detection, monitoring and modeling

This paper tells the story of a landslide, its origins, its activity and the actions undertaken to mitigate the risks that it poses. The Rotolon landslide is a large Deep-seated Gravitational Slope Deformation (DGSD), located in the Eastern Italian Alps, whose unremitting movements provide a sediment supply for large-scale debris flow events. It has been active since at least 1789, threatening the valley where the thermal baths town of Recoaro Terme is located. In 2010, a major reactivation of the landslide channelled 320,000 m3 of material towards the town causing significant concern, the evacuation of the exposed population and threatening several buildings. A few days after the emergency, the personnel of the Research Institute for Geo-Hydrological Protection of the Italian Research Council (IRPI-CNR) deployed a monitoring system consisting of an automatic total station, several extensometers and web cameras to monitor the evolution of the unstable slope and set up an early warning and alarm system equipped with sirens to warn the local population. Subsequently, after the emergency phase, the 2010 event was studied through multi-temporal LiDAR Digital Terrain Models (DTMs) and modeling. The authors have continued monitoring and actively studying this landslide ever since. In 2020, a new LiDAR survey of the area allowed assessment of the sediment dynamics within the catchment through the comparison with the post-2010 event LiDAR DTM. Based on DEM of difference maps, new insight into the behaviour of the catchment emerged, which appears to be influenced both by natural processes and anthropic activities. The authors were able to assess the amount of sediment that could be stored in the channel without causing overflooding and to calculate the expected damage to the built environment should another event occur. Furthermore, the considerable amount of data collected by the monitoring system throughout the years has allowed identification of two active sectors of the DGSD that may be prone to detachment, and through numerical modeling, future hazard scenarios were produced. Based on these outcomes, a second-tier targeted monitoring campaign was implemented, consisting of a network of four permanent GNSS receivers, additional topographic benchmarks and web cameras, and a new early warning protocol, in an ever-updating cycle of monitoring, modeling and mitigation.

Flash flood prediction modeling in the hilly regions of Southeastern Bangladesh: A machine learning attempt on present and future climate scenarios

Flash floods are highly destructive, and their frequency and intensity are expected to escalate due to climatic changes. This study thus investigated flash flood susceptibility (FFS) by applying machine learning algorithms and climate projection to predict both present and future hazard scenarios in the southeastern hilly regions of Bangladesh. To predict FFS, we evaluated twelve flood-influencing variables: elevation (EL), slope (SL), aspect (AS), drainage density (DD), distance to stream (DS), topography roughness index (TRI), stream power index (SPI), topographic wetness index (TWI), soil permeability (SP), precipitation (PR), land use and land cover (LULC) and normalized difference vegetation index (NDVI). Earth observation data, field surveys, and past flood records were used to create a detailed flood inventory. Among the machine learning models tested, the random forest (RF) algorithm outperformed others, including support vector machine (SVC), logistic regression (LR), and extreme gradient boosting (XGBoost), and was subsequently used for flood susceptibility mapping based on future precipitation projections under two Sixth Coupled model intercomparison project (CMIP6) climate change scenarios: SSP1-2.6 and SSP5-8.5. Our findings indicated that the areas at high to very high risk of flooding are projected to increase significantly under both the SSP1-2.6 and SSP5-8.5 scenarios. Initially, around 38 % of the studied region had high to very high flood susceptibility, but this is expected to rise to 40–42 % over the projected time periods. These spatial delineations of flood-prone areas can provide guidance for developing effective mitigation and adaptation strategies to address the adverse impacts of flash flooding in the hilly river basins of Bangladesh.

Wealth Over Woe: Global Biases in Hydro‐Hazard Research

AbstractFloods, droughts, and rainfall‐induced landslides are hydro‐hazards that affect millions of people every year. Anticipation, mitigation, and adaptation to these hazards is increasingly outpaced by their changing magnitude and frequency due to climate change. A key question for society is whether the research we pursue has the potential to address knowledge gaps and to reduce potential future hazard impacts where they will be most severe. We use natural language processing, based on a new climate hazard taxonomy, to review, identify, and geolocate out of 100 million abstracts those that deal with hydro‐hazards. We find that the spatial distribution of study areas is mostly defined by human activity, national wealth, data availability, and population distribution. Hydro‐hazard events that impact large numbers of people lead to increased research activity, but with a strong disparity between low‐ and high‐income countries. We find that 100 times more people need to be affected by hazards before low‐income countries reach comparable research activity to high‐income countries. This “Wealth over Woe” bias needs to be addressed by enabling and targeting research on hydro‐hazards in highly impacted and under‐researched regions, or in those sufficiently socio‐hydrologically similar. We urgently need to reduce knowledge base biases to mitigate and adapt to changing hydro‐hazards if we want to achieve a sustainable and equitable future for all global citizens.

Projecting urban flood risk through hydrodynamic modeling under shared socioeconomic pathways

Under future climate change, accurate risk assessment of urban flooding disasters is paramount for effective adaptation and mitigation strategies. However, conventional indicator-based assessment methods often fall short of accurately capturing the complexity of flooding dynamics. Current research predominantly focuses on predicting future hazard shifts while overlooking changes in other critical indicators. In this study, we establish a comprehensive index system for risk assessment, and quantified future changes in most indicators, utilizing the InfoWorks ICM model for hazard simulation and the CLUMondo model for land use predictions. Based on risk assessment results and regional characteristics, we further analyze the key factors driving future risk and discuss corresponding measures. The results indicate an exacerbation of future urban flood risk, with an 18% increase in high risk areas, primarily concentrated in the center of the study area. The dominant indicators are inundation depth and land use over the whole study area. However microtopography significantly affects risk in low-lying areas. Overall, under higher emission scenarios, the influence of GDP and population rises. These findings offer methodological insights for future urban flood risk assessment research and provide policymakers with valuable guidance to develop targeted adaptation measures in response to climate change.

Afterslip and Creep in the Rate‐Dependent Framework: Joint Inversion of Borehole Strain and GNSS Displacements for the Mw 7.1 Ridgecrest Earthquake

AbstractThe elusive transition toward afterslip following an earthquake is challenging to capture with typical data resolution limits. A dense geodetic network recorded the Mw 7.1 Ridgecrest earthquake, including 16 Global Navigation Satellite System (GNSS) stations and 3 borehole strainmeters (BSM). The sub‐nanostrain precision and sub‐second sampling rate of BSMs bridges a gap between conventional seismologic and geodetic methods, exemplified by atypical postseismic shear strain reversals observed at nearfield (&lt;2 km) station B921 that remain unexplained. We jointly invert GNSS displacements and BSM strains for coseismic and postseismic slip spanning hours to months over 7 independent periods. Cosiesmically, our model resolves the largest slip magnitudes of up to 6.6 m on the mainshock rupture plane, with similar patterns to other inferred slip distributions. The foreshock fault appears to slip coincidently with mainshock, revealing potential asperities activated during the preceding Mw 6.4 event. Postseismically, the best‐fitting models adhere to mechanical rate‐and‐state expectations of logarithmically decaying slip adjacent to the coseismic rupture terminus, and where deep rheologic conditions favor creep. Most spatial variation occurs in the early postseismic timeframe (&lt;1–2 weeks), with evidence for regional rheologic control and static stress dependence. Triggered creep on the neighboring Garlock Fault unexpectedly persists for &gt;178 days—further highlighting the importance of fault networks in postseismic stress redistribution, critical to assessing future hazard.

PALEO TSUNAMIS AND STORM SURGES RECORDED BY FOSSIL CORAL ON YAKUSHIMA ISLAND, JAPAN

ABSTRACTYakushima is a small, mountainous island off southern Kyushu, Japan. Its proximity to active volcanos and subduction zones leaves Yakushima vulnerable to large megathrust earthquakes and tsunamis, in addition to powerful typhoons and storm surges. These hazardous events deposit beach boulders: large rocks moved above sea-level by powerful waves. By radiocarbon dating the fossilized coral within these boulders, one can derive age estimates of the hazard events. Reliably estimating the magnitude and timing of geological events in the historical record is vital for future hazard prediction and mitigation. In this study, we estimated the deposition age of ten boulders on the north coast of Yakushima to infer potential paleo tsunamis and storm surges. We found that large wave events have occurred frequently throughout the Holocene. Based on the boulders’ ages, we identified four potential deposition events at 1986–2692 cal yr BP, 3522–4075 cal yr BP, 4773–5232 cal yr BP, and 6187–6638 cal yr BP. These deposits are likely a result of storm surges, or tsunamis from nearby volcanic activity or subduction earthquakes. Another set of boulders dated to 5125–5738 cal yr BP were likely exposed due to a decline in sea-level following the Holocene high sea-level stand. Further modelling could determine the wave height necessary to move the boulders and distinguish between storm and tsunami deposits. This is especially pertinent given the high frequency of coastal geohazards, and the likelihood of similar hazards impacting southeast Japan in the future.

Vulnerability to extreme weather events: mapping future hazards in Wielkopolska region, Poland

The aim of this study is to assess future hazards due to extreme meteorological events in the Wielkopolska region, Poland, based on five climate model projections and three scenarios: SSP126, 370, and 585. The paper analyzes the changes of mean and extreme precipitation, mean and extreme temperatures, and humidity index, as well as changes in difference between maximum temperatures observed from day to day and changes in difference between mean atmospheric pressure at the sea level observed from day to day. Additionally, we look at possible future occurrence of wildfires due to changes in fire weather conditions. Based on climate model projections, future hazard due to extreme meteorological events in Wielkopolska region is to be more serious and will be most noticeable in the end of twenty-first century and for two higher scenarios: SSP370 and SSP585. For near future, 2021–2050, projected conditions of meteorological extremes for analyzed scenarios are quite consistent. Therefore, there is a strong need for implementing adaptation actions. Nevertheless, such activities are so far lacking, and several adaptation options are not present in local and national legislation, even though they are recognized as effective.

Source parameters and aftershock pattern of the October 7, 2021, M5.9 Harnai earthquake, Pakistan

On October 7, 2021, a magnitude 5.9 earthquake struck the Harnai (Baluchistan) region of Pakistan, causing several fatalities and injuries within the epicentral area. First-order tectonic deformation in this region is caused by the convergence of the Indian Plate with respect to the Eurasian Plate. The Katwaz Block hinders the motion of the Indian Plate, resulting in the formation of strike-slip faults. In this study, the P-wave first-motion polarity technique was used to determine the mainshock faulting style. Cyclic scanning of the polarity solutions was applied to determine the most suitable focal mechanism solution among the available solutions generated by the FOCMEC (focal mechanism) software. The nodal planes correspond to different faulting styles (i.e., thrust and strike-slip faulting). A nodal plane oriented in the NW-SE direction corresponded to a strike-slip mechanism, which was considered to be the fault plane. Tectonically, this earthquake was associated with the Harnai-Karahi strike-slip fault zone owing to the fault strike and direction of slip. The apparent stress drop, fault length, and moment magnitude of the Harnai earthquake were 35.4 bar, 6.1 km, and 5.9, respectively. A lower b-value for the Gutenberg-Richter law was observed prior to the earthquake. Higher α- than b-values (α >b) indicate that this earthquake was governed by large events as opposed to small-magnitude events. The Harnai sequence had a decay exponent close to unity, lasted for 145 days, and produced few aftershocks. The study will help the future hazard mitigation in the region.

Modeling of Future Streamflow Hazards in Interior Alaska River Systems and Implications for Applied Planning

There is a growing need for proactive planning for natural hazards in a changing climate. Computational modeling of climate hazards provides an opportunity to inform planning, particularly in areas approaching ecosystem state changes, such as Interior Alaska, where future hazards are expected to differ significantly from historical events in frequency and severity. This paper considers improved modeling approaches from a physical process perspective and contextualizes the results within the complexities and limitations of hazard planning efforts and management concerns. Therefore, the aim is not only to improve the understanding of potential climate impacts on streamflow within this region but also to further explore the steps needed to evaluate local-scale hazards from global drivers and the potential challenges that may be present. This study used dynamically downscaled climate forcing data from ERA-Interim reanalysis datasets and projected climate scenarios from two General Circulation Models under a single Representative Concentration Pathway (RCP 8.5) to simulate an observational gage-calibrated WRF-Hydro model to assess shifts in streamflow and flooding potential in three Interior Alaska rivers over a historical period (2008–2017) and two future periods (2038–2047 and 2068–2077). Outputs were assessed for seasonality, streamflow, extreme events, and the comparison between existing flood control infrastructure in the region. The results indicate that streamflow in this region is likely to experience increases in seasonal length and baseflow, while the potential for extreme events and variable short-term streamflow behavior is likely to see greater uncertainty, based on the divergence between the models.

Structural Analysis of the Sympathetic Restoration and Conservation of the Gopinath Temple, Kathmandu, Nepal

The sympathetic restoration and conservation of built cultural heritage play a significant role in the management and preparedness for future climate scenarios by facilitating adaptive reuse, enhancing cultural resilience, preserving traditional knowledge, and boosting tourism. The importance of restoring damaged heritage sites after an earthquake drew international attention to Nepal after the 2015 Gorka Earthquake. UNESCO established an office in Kathmandu to promote the restoration of tangible and intangible heritage in the area. This included developing structural analyses of buildings with historical and cultural value that, due to their nature, cannot be intervened with the same methodology as modern buildings. In this paper, the case study of the earthquake-damaged Gopinath temple is discussed. First, an initial visual inspection phase and the following diagnosis of the structure are discussed. Then, the results from a series of static and dynamic structural analyses performed to determine the safety level of the structure, together with a sensitivity analysis, are presented. A sympathetic intervention proposal capable of increasing the temple’s safety level, and based on the addition of timber plates, has resulted in substantial improvements in the lateral behavior of the structure. The proposed intervention is deemed sustainable and able to increase the resilience of the temple in the face of future hazards.

Multitimescale Template Matching: Discovering Eruption Precursors across Diverse Volcanic Settings

Abstract Volcanic eruptions pose significant risks, demanding precise monitoring for timely hazard mitigation. However, interpreting noisy seismic data for eruptive precursors remains challenging. This study introduces a novel methodology that extends an earlier time-series feature engineering approach to include template matching against prior eruptions. We aim to identify subtle signals within seismic data to enhance our understanding of volcanic activity and future hazards. To do this, we analyze the continuous seismic record at a volcano and identify the time-series elements that regularly precede eruptions and the timescales over which these are observable. We conduct tests across various time lengths, ranging from 1 to 60 days. For Copahue (Chile/Argentina), Pavlof (Alaska), Bezymianny (Russia), and Whakaari (New Zealand) volcanoes, we confirm statistically significant eruption precursors. In particular, a feature named change quantiles (0.2–0.8), which is related to the conditional dynamics of surface acceleration at the volcano, emerges as a key indicator of future eruptions over 14-day timescales. This research offers new methods for real-time seismovolcanic monitoring, minimizing the effects of unknown, spurious noise, and discerning recurrent patterns through template matching. By providing deeper insights into pre-eruptive behavior, it may lead to more effective hazard reduction strategies, enhancing public safety around active volcanoes.

Origins and nature of large explosive eruptions in the lower East Rift Zone of Kīlauea volcano, Hawaii: Insights from ash characterization and geochemistry

Several powerful explosive eruptions have taken place in the populated lower East Rift Zone of Kīlauea within the past ∼750 years. These have created distinctive landforms, including a tephra rim enclosing Puʻulena Crater immediately south of the Puna Geothermal Venture power station, a tuff cone at Kapoho Crater near the eastern cape of the Island of Hawaiʻi, and a set of littoral cones, the Sand Hill in Nānāwale, where the 1840 lava flow poured into the ocean. Kapoho Crater tuff cone is the largest of these recent pyroclastic features. Mineral, glass, and melt inclusion analyses of tuff cone ash and later fissure-related scoriaceous materials also found within the crater indicate slightly evolved basaltic magmas (1120–1130 °C) that are compositionally similar to parts of the effusive lower East Rift Zone eruptions in 1955 and 2018. Tuff cone magmas were stored at depths of ∼2.5–3.5 km and had pre-eruptive volatile contents (0.5–0.8 wt% H2O, 280–340 ppm CO2, 1400–1800 ppm S) similar to other Kīlauea eruptions (e.g., 1959, 1960), suggesting that internal magma properties were unlikely to account for the unusual explosiveness of this eruption. Tephra componentry, grain-size analyses, and field observations confirm that the cone grew during a phreatomagmatic eruption mostly of vitric ash, probably where a fissure opened across the coastline or shallow ocean floor nearby. Supporting this hypothesis is the identification of at least two genera of marine diatoms within tuff cone strata. Sand Hill littoral cone ash is also vitric like that of Kapoho Crater, but distinctly coarser with abundant fluidal ejecta represented. In contrast, the Puʻulena Crater eruption deposited lithic ash and related blocks with minor juvenile magmatic contribution; a phreatomagmatic eruption that was dominantly phreatic. Differences in eruption styles are related to unique mechanics that tephra analyses help us interpret. While powerful explosive eruptions in the lower East Rift Zone are rare, they present a definite future hazard for inhabitants in this part of Hawaii.

Rapid Finite-Fault Models for the 2023 Mw 7.8 Kahramanmaraş, Türkiye, Earthquake Sequence

Abstract In the immediate aftermath of devastating earthquakes such as in the 6 February 2023 Kahramanmaraş sequence in southcentral Türkiye, key stakeholders and the public demand timely and accurate earthquake information. Especially for large events, finite-fault models provide important insights into the rupture process and enable interpretation of the observed ground shaking, which can improve situational awareness and facilitate rapid assessment of future hazards. Using strong-motion waveforms recorded during the Kahramanmaraş sequence, we simulate a real-time playback and calculate how a finite-source model computed with the Finite-fault rupture Detector (FinDer) algorithm would evolve for the Mw 7.8 Pazarcık, Mw 7.6 Elbistan, and Mw 6.4 Yayladağı earthquakes. Using template matching FinDer compares observed and predicted ground-motion acceleration amplitudes to determine the orientation and spatial extent of fault rupture. We test both generic crustal and fault-specific templates from ground-motion models and rupture geometries of the east Anatolian and Çardak–Sürgü faults. In the second step, we estimate the seismic slip along the source models from the backprojection of the seismic displacement amplitudes. The algorithms achieve excellent performance for all three earthquakes, and the final source models and slip profiles available within tens of seconds of the rupture nucleation match well with models computed days to weeks after the events occurred. The temporal evolution of the source models for the Pazarcık and Elbistan earthquakes suggests that FinDer can provide insight into the rupture kinematics of large earthquakes. Cascading instrument failures as well as power and data telemetry interruptions during the Pazarcık earthquake led to an early termination of signals at a significant number of near-source stations. We show that FinDer is robust enough to cope with this type of degradation in network performance that can occur in large earthquakes, in general.