Catastrophic Volcanic Eruptions Research Articles

An upper-crust lid over the Long Valley magma chamber.

Geophysical characterization of calderas is fundamental in assessing their potential for future catastrophic volcanic eruptions. The mechanism behind the unrest of Long Valley Caldera in California remains highly debated, with recent periods of uplift and seismicity driven either by the release of aqueous fluids from the magma chamber or by the intrusion of magma into the upper crust. We use distributed acoustic sensing data recorded along a 100-kilometer fiber-optic cable traversing the caldera to image its subsurface structure. Our images highlight a definite separation between the shallow hydrothermal system and the large magma chamber located at ~12-kilometer depth. The combination of the geological evidence with our results shows how fluids exsolved through second boiling provide the source of the observed uplift and seismicity.

The 1257 CE cataclysmic eruption of Samalas volcano (Indonesia) revealed by indigenous written sources: Forgotten kingdoms, emergency response, and societal recovery

Historical and archaeological findings have revealed that many human civilizations have been strongly affected by natural hazards, such as volcanic eruptions. An issue that still lacks attention is the response of ancient populations following eruptions as well as their resilience strategies. Three written sources from Lombok, Indonesia, provide descriptions of the ancient landscape of Lombok and the population's response to the Samalas volcano eruption in 1257 CE. The sources depict the conditions of Lombok and the surrounding areas during the pre-, onset-, and post-eruption phases of a catastrophic volcanic eruption with a volcanic explosivity index 7. Various responses of the inhabitants to the eruption are described in the sources, such as fleeing to the hills, avoiding hazards, and escaping to neighboring villages or islands. Several geographic features and toponyms are mentioned, allowing us to reconstruct the evacuation process during the crisis period. The sources also describe recovery strategies in the post-eruption period, including governance strategies, the rebuilding of cities and villages, and agriculture. The historical record suggests that Lombok may have taken up to a century to recover from the eruption and that new kingdoms and principalities became established by the fourteenth century. Disaster management related to the eruption is described in the texts from Lombok, but not in older written sources from Indonesia.

Geoheritage and geodiversity aspects of catastrophic volcanic eruptions: Lessons from the 15th of January 2022 Hunga Tonga - Hunga Ha'apai eruption, SW Pacific

On the 15th of January 2022, a massive hydrovolcanic eruption at Hunga Tonga-Hunga Ha'apai in Tonga (SW Pacific) sent shockwaves in the near-field regime, close to the volcano. The far-field disturbances that encircled the globe were of a slower velocity. The most prominent disturbance was the Lamb wave, with the rest of the disturbances being a variety of gravity waves travelled around the globe and instantly became an international headline story. The eruption generated atmospheric pressure waves recorded multiple times across the globe, triggered a tsunami, and injected highly fragmented pyroclasts up to 55 km into the atmosphere. Enduring several hours, a series of individual large blasts generated an unprecedented lightning “show” recorded by the lightning detection networks, such as Vaisala. Consequences were devastating to the local community and the tsunami was felt across the Pacific and beyond. The impact of the eruption was truly global and comparable to the Krakatau 1883 eruption. A question we pose here is which geoheritage elements were created and preserved after the eruption. First reports confirmed that while fine ash was reported on land about 100 km from the source, most deposits were thin (mm-cm thick). This indicates that it is unlikely that any major section will be preserved, especially in the years following the event given the tropical setting. In addition, most of the ash fell into the Pacific Ocean, leaving no visible mark of this catastrophe. Unfortunately, the proximal region (e.g., the vent site) has also been destroyed, leaving only limited in-situ geoheritage elements likely to be accessible in the future. This poses a problem for human societal memory, as major catastrophic events in the collective memory of a community may only persist for a few decades, even when significant eruptive features may be preserved. Without “visible” geoheritage elements, this time will likely be much shorter. Geocultural elements (oral traditions or cultural activities) are likely to preserve and transmit information within the local communities for a longer period, but their accessibility and decoding may face difficulties in the absence of physically preserved evidence. Therefore, we consider it is important to trace and explore these geocultural elements through a mix of traditional and western approaches of community engaged activities. For example, the Pacific region has experienced several similar large-scale eruptions in historic times, and a few of them resulted in preserved geoheritage elements such as superb sections of the 1452–53 CE Kuwae eruption in Vanuatu. While these sites are locally known, their appearance and their geological context are not evidently and immediately considered as part of a major volcanic system, as they do not fit the common human perception of volcanoes as large conical mountains. Such visual perceptions do not align with the common near-sea level/shallow subaqueous caldera-dominated systems such as the location of the recent Tonga event. In achieving a better understanding in local communities of this type of geohazard, the geoheritage and geoeducation values of those rare geosites will increase significantly over time.

Analysis of preparedness in dealing with volcanic eruption disaster, study case: SMPN 2 Ngemplak Sleman regency

In the region of Indonesia, several volcanoes are still active and can erupt at any time. Knowledge of volcanic eruptions is very important for residents around the volcano because it will be related to the preparedness of residents at the time of volcanic eruptions. If the knowledge and preparedness of the citizens are good, it will prevent so many victims. This study aimed to analyze students’ levels of disaster preparedness in the face of catastrophic volcanic eruptions. The research used is a quantitative descriptive method with a research sample of 32 students of class VII SMPN 2 Ngemplak taken by cluster random sampling. The data collection techniques used are interviews, and questionnaires. Based on the results of the study, it can be concluded that the student preparedness index for each indicator of preparedness in the dealing of a catastrophic volcanic eruption is (1) knowledge and attitude 72.40 categorized ready, (2) emergency planning 59.38 categorized almost ready (3) early warning system 61.72 categorized almost ready and (4) resource mobilization is in the index 64.06 with almost ready category. So that the average index value of the four parameters of disaster preparedness of volcanic eruptions is 64.72 with the category almost ready. This research can be used as a basis for the development of teaching materials to help reduce the risk of volcanic eruptions.

Traces of Catastrophic Volcanic Eruptions in the Moscovian Stage (Middle Pennsylvanian, Carboniferous) in the Central East European Platform

Traces of Catastrophic Volcanic Eruptions in the Moscovian Stage (Middle Pennsylvanian, Carboniferous) in the Central East European Platform

Giant palaeotsunami in Kiribati: Converging evidence from geology and oral history

AbstractFor tsunami science within Oceania, the vast Central and Western Pacific (CEWEP) is an anomalous region because of the scarcity of historical tsunami observations and the complete absence of dated palaeotsunami evidence. This paper therefore records the first dated high‐magnitude palaeotsunami event within the CEWEP region. A combination of both geological data and oral history is provided for a palaeotsunami that struck remote Makin island, northernmost of the Gilbert Islands in Kiribati, toward the end of the 16th century. A previously undocumented oral tradition of giant waves is well known to the people of Makin. Narration of this legend by the Wiin te Maneaba, traditional storyteller on Makin, provided important details supporting a tsunami hypothesis. The legend preserves credible information surrounding the giant‐wave origin of Rebua and Tokia, two prominent subaerial megaclasts of blade and block geometry that were transported 80–130 m shorewards from the reef‐edge source and deposited in sideways and inverted orientations. From available hydrodynamic flow transport equations, minimum flow velocities of 7.3–16.3 m s−1 were generated, depending on whether the reefblocks were rotated or lifted onto the reef platform. The youngest U‐Th age‐dates for fossil corals retrieved from the reefblocks give a maximum age for the palaeotsunami of circa AD 1576. Several far‐field Pacific Rim and regional possibilities exist for tsunamigenesis. These include subduction‐zone seismicity and catastrophic volcanic eruption, both of which have been linked to earlier (late 15th century) palaeotsunami events recorded elsewhere in the Pacific Islands. However, the available evidence here suggests that the ~AD 1576 Makin palaeotsunami was more likely to have been locally generated by tsunamigenic offshore submarine slope failure close to Makin's western reef, associated with the giant arcuate bight structure that characterizes the northern rim of Butaritari atoll.

Catastrophic Volcanic Eruptions: Causes and Mechanisms

One of the main natural disasters is explosive volcanic eruptions, often lasting 2–4 months. It is obvious that such eruptions of volcanoes cause simultaneous mass release of gas bubbles from the melts of their shallow peripheral chambers, which must lead to a sharp increase in the volume of material contained in them, i.e., to explosions. It is shown that the main prerequisite for an explosive eruption is a sharp decrease in the solubility of water in melts known from experimental data at pressures less than 1 kbar corresponding to a depth of 3.5 km (Shilobreeva et al., 1991). Therefore, rising water-saturated melts characteristic of suprasubduction (convergent) settings, automatically become supersaturated with water when they reach depths of 3–4 km, and are thus an explosive mixture that is ready to blow up at any moment. However, the release of gas bubble nuclei is a very energy-consuming process, and will not begin by itself. We believe that the trigger for a catastrophic explosion can be one of the earthquakes preceding the eruption, which resonates with self-oscillations in the peripheral chamber beneath the volcano. This greatly increases the power of the impulse and helps to overcome the energy barrier. It is shown that the necessary and sufficient conditions for the occurrence of a catastrophic eruption are: 1) the existence of a shallow chamber with a water-supersaturated magma melt; the presence of other volatiles (CO2, SO3 etc.) does not play a significant role here; 2) the occurrence of a triggering earthquake that is in resonance with self-oscillations in this chamber; and 3) the presence of a continuous supply of the peripheral chamber beneath the active volcano with new melt portions, thus prolonging the eruption.

Laboratory Investigation of Particle‐Scale Factors Affecting the Settling Velocity of Volcaniclastic Dust

AbstractIceland contains some of the largest and most active dust sources in the Arctic, with the frequency of major emission events increasing in the wake of catastrophic volcanic eruptions, such as the 2010 Eyjafjallajökull eruption. Relatively juvenile Icelandic volcaniclastic dust particles are porous and highly angular, and they frequently bear ultrafine nanoscale dustcoats. Their low density is speculated to affect deposition rates in the atmosphere, while substantial amounts of water adsorbed onto their expansive surface area may affect nucleation, aggregation, and settling. Using a 2‐D laser Doppler anemometer, the present paper reports on a set of highly controlled fall column experiments designed to evaluate the dependency of the settling velocity upon particle morphology (e.g., size, shape, density, and surface area) and relative humidity (RH). Measurements for samples obtained from four Icelandic field sites are compared to those for solid glass spheres of similar diameter. The results confirm that the amount of adsorbed water increases with RH and the particle specific surface area. Higher dust concentrations are found to favor particle interaction and the formation of aggregates, especially at higher RH. Under dry conditions (20 % < RH < 30 % ), the horizontal drift velocity measured for the angular, porous Icelandic particles exceeds that observed for solid glass spheres, although these measurements are an order of magnitude smaller than the vertical velocity. As compared to particle diameter, shape does not appear to influence either the settling rate or drag coefficient at Reynolds numbers ≤10−2, owing to the dominance of viscous effects over form drag.

When There Is No Offset: A Demonstration of Seismic Diffraction Imaging and Depth‐Velocity Model Building in the Southern Aegean Sea

AbstractA vast majority of marine geological research is based on academic seismic data collected with single‐channel systems or short‐offset multichannel seismic cables, which often lack reflection moveout for conventional velocity analysis. Consequently, our understanding of Earth processes often relies on seismic time sections, which hampers quantitative analysis in terms of depth, formation thicknesses, or dip angles of faults. In order to overcome these limitations, we present a robust diffraction extraction scheme that models and adaptively subtracts the reflected wavefield from the data. We use diffractions to estimate insightful wavefront attributes and perform wavefront tomography to obtain laterally resolved seismic velocity information in depth. Using diffraction focusing as a quality control tool, we perform an interpretation‐driven refinement to derive a geologically plausible depth‐velocity model. In a final step, we perform depth migration to arrive at a spatial reconstruction of the shallow crust. Further, we focus the diffracted wavefield to demonstrate how these diffraction images can be used as physics‐guided attribute maps to support the identification of faults and unconformities. We demonstrate the potential of this processing scheme by its application to a seismic line from the Santorini Amorgos Tectonic Zone, located on the Hellenic Volcanic Arc, which is notorious for its catastrophic volcanic eruptions, earthquakes, and tsunamis. The resulting depth image allows a refined fault pattern delineation and, for the first time, a quantitative analysis of the basin stratigraphy. We conclude that diffraction‐based data analysis has a high potential, especially when the acquisition geometry of seismic data does not allow conventional velocity analysis.

RAPID SURVEYS REVEAL HEALTHY CORAL-SPONGE COMMUNITIES ON KRAKATAU REEFS

The Krakatau Islands in the Sunda Strait have been significantly impacted by catastrophic volcanic eruptions in 1883 and 2018. The marine habitats are not well studied, neither in the past nor in the present. This research is a report on the distribution and ecology of corals and sponges in the Krakatau Volcanic Complex at the three islands of Anak Krakatau, Rakata, and Panjang. This study used 100 m transects long in 5–7 m depth. Hard coral and soft coral communities are found to live with a coverage varied between 25-53% and 0-24%. Dead coral skeletons covered 14–40% of the surveyed area and did not seem to affect the abundance of sponges recorded. The Sponges occupied 0–6% of the area, and they often acted as coral competitors, shaping the benthic ecosystems. The recorded sponges only belong to the Demospongiae class, which are the Suberitid species that are commonly found in Indonesian waters, e.g., Amorphinopsis excavans, Protosuberites collaris, and Terpios sp. The excavating sponge Cliona cf. orientalis was frequently found to be a successful competitor of massive Porites sp., aggressively overgrowing live parts of the coral. Two Haliclona species and Mycale relicta colonized dead coral skeleton. Overall, the benthic communities appear healthy and are comparable to other similar locations that are not affected by volcanic activity.

Prevention of Catastrophic Volcanic Eruptions, Large Earthquakes underneath Big Cities, and Giant Earthquakes at Subduction Zones

Catastrophic volcanic eruptions, large earthquakes beneath big cities, or giant earthquakes at subduction zones are apparently the biggest problems facing the sustainability of human society. However, imminent prediction methods for these events have never been established, except that volcanic eruptions can only be predicted by exceptional efforts by dedicated researchers. Even if a prediction method has been established, the method cannot significantly reduce infrastructure damage, although it could slightly reduce the number of fatalities. On the other hand, prevention of eruptions or earthquakes could significantly reduce, not only the number of fatalities, but also infrastructure damage. Therefore, the authors propose (1) gradual energy release by supercritical power generation to prevent catastrophic eruptions; (2) gradual seismic energy release by injecting water into seismic sources to prevent large earthquakes beneath big cities; and (3) exploding existing nuclear warheads underground to prevent giant earthquakes at subduction zones. Necessary technical developments, costs, risks, and problems will also be explained.

Contrasting catastrophic eruptions predicted by different intrusion and collapse scenarios

Catastrophic volcanic eruptions triggered by landslide collapses can jet upwards or blast sideways. Magma intrusion is related to both landslide-triggered eruptive scenarios (lateral or vertical), but it is not clear how such different responses are produced, nor if any precursor can be used for forecasting them. We approach this problem with physical analogue modelling enhanced with X-ray Multiple Detector Computed Tomography scanning, used to track evolution of internal intrusion, and its related faulting and surface deformation. We find that intrusions produce three different volcano deformation patterns, one of them involving asymmetric intrusion and deformation, with the early development of a listric slump fault producing pronounced slippage of one sector. This previously undescribed early deep potential slip surface provides a unified explanation for the two different eruptive scenarios (lateral vs. vertical). Lateral blast only occurs in flank collapse when the intrusion has risen into the sliding block. Otherwise, vertical rather than lateral expansion of magma is promoted by summit dilatation and flank buttressing. The distinctive surface deformation evolution detected opens the possibility to forecast the possible eruptive scenarios: laterally directed blast should only be expected when surface deformation begins to develop oblique to the first major fault.

Hirarki Wilayah Kota Ternate Pasca Pengembangan Kawasan Waterfront City

<p class="Abstract"><em>Ternate waterfront city development 2006-2015 initiative was triggered by the limitation of land use due to high population increase, geographical, and topographical constraints of the region, the threat of catastrophic volcanic eruption as well as national and provincial development strategy. The purpose of this study was to analyse the urban service hierarchy inside the city. The methodology used in this research was scalogram analysis with infrastructure variable. The regional hierarchy analysis after the development of waterfront city (2005-2011) showed that there were aspect of the development of infrastructure and accessibility, where coastal village was more development than non coastal village has waterfront city area.</em></p>

Genesis of the boron potential of the Taukha metallogenic zone, Sikhote Alin, and boron sources during formation of the Dal’negorsk boron deposit

It is shown that the formation of borosilicate skarn in the Taukha metallogenic zone completes a series of successive stages of the formation and transformation of the folded sequences of the Taukha accretionary wedge. The Early Cretaceous sedimentary stage, including accumulation of detrital tourmaline-rich sedimentary rocks, was implemented in the marginal sea of the Paleopacific Sino-Korean segment. In the Turonian–Campanian, the boron-bearing folded sequences of the accretionary wedge were involved in anatexis to generate siliceous S-type boron-bearing melts. The thus-formed magmatic chambers were emptied during catastrophic volcanic eruptions. At the final Middle Campanian volcanic stage, fluid-magmatic differentiation of the melt in the residual chambers generated fluid flow. The infiltration interaction of the fluids, which inherited enrichment in boron, with limestones of the olistostrome sequence resulted in the formation of a giant zone of grossular–wollastonite skarns and danburite lodes. The boron potential of the Taukha boron–lead–zinc metallogenic zone may be considered as a reproduction of the Precambrian boron metallogeny of the eastern Eurasian margin, which was implemented in the Late Mesozoic during recycling of the continental crust.

Stress Field Control during Large Caldera-Forming Eruptions

Crustal stress field can have a significant influence on the way magma is channelled through the crust and erupted explosively at the surface. Large Caldera Forming Eruptions (LCFEs) can erupt hundreds to thousands of cubic kilometres of magma in a relatively short time along fissures under the control of a far-field extensional stress. The associated eruption intensities are estimated in the range 109 - 1011 kg/s. We analyse syn-eruptive dynamics of LCFEs, by simulating numerically explosive flow of magma through a shallow dyke conduit connected to a magma chamber that in turn is fed by a deeper magma reservoir, both under the action of an extensional far-field stress. Results indicate that huge amounts of high viscosity silicic magma can be erupted over timescales of a few to several hours. Our study provides answers to outstanding questions relating to the intensity and duration of catastrophic volcanic eruptions in the past. In addition, it presents far-reaching implications for the understanding of dynamics and intensity of large-magnitude volcanic eruptions on Earth and to highlight the necessity of a future research to advance our knowledge of these rare catastrophic events.

Building a city: Korean capitalists and navy nostalgia in “overheated” Subic Bay

ABSTRACTOver the course of just half a year, a catastrophic volcanic eruption and an unexpected political victory would come to act upon and dramatically alter the location of Subic Bay in the Philippines. As a consequence, the annus mirabilis of 1991 brought a (temporary) end to more than a century of US tutelage for the Philippines. Subic Bay, an area that had been economically, politically and socially dependent on the patronage of the US Navy, was now undergoing major transformations. The land and infrastructure left behind by the Americans were turned into the Philippines’ largest special economic zone, becoming the vanguard platform that allowed for the introduction of an “overheated” form of economic globalization into the Philippines. Amongst the foreign direct investors now active in Subic, a South Korean shipbuilder has become a new hegemon, building a giant shipyard inside the bay that today employs 34,000 Filipino workers. Paying particular attention to how contested gendered relations between foreign sailors and the local population have come “to build this city” during the cold war, the rapidly urbanizing Subic Bay area is analysed through what I call “navy nostalgia”: the widespread, yet rather equivocal longing for the return of the US Navy that needs to be read in light of the recent arrival of the South Korean shipbuilder.

Late Pleistocene and Holocene volcanic catastrophes in Kamchatka and in the Kuril Islands. Part 1. Types and classes of catastrophic eruptions as the leading components of volcanic catastrophism

We advance our own definitions of the following terms: catastrophic volcanic eruption (CE), catastrophic supereruption (CSE), different-rank and different-type episodes and phases of volcanic catastrophism (VC). All eruptions are subdivided into three classes according to the volume and weight of the erupted and transported (juvenile and resurgent) material, whatever its chemical composition: class I (>0.5 km3), class II (≥5 km3), and class III, or supereruptions (>50 km3). We characterize the types and varieties of CEs and CSEs, with most of these being the main components of identified VC episodes and phases. The primary phenomena to be considered include catastrophic events of the 19th to 21st centuries, not only in the Kuril–Kamchatka region, but also in other volcanic areas. These events have been studied in detail by modern methods and can serve as approximate models to reconstruct similar past events, especially regarding their dynamics, productivity, and catastrophic impact.

The Last Volcano / Det siste utbruddet

A story of a catastrophic volcanic eruption and its aftermath is twice told by a woman before the slowly turning image of contemporary urban landscape. The Last Volcano was filmed at docks in Bergen Norway using panoramic animation. The imagery of a peaceful and prosperous contemporary urban landscape is juxtaposed with an 18th century account of widespread death and crop-loss caused by an eruption of an Icelandic volcano. The work was filmed during the period of the 2011 eruptions of the Eyjafjallajökull volcano that impacted European air and transport.

KEBUTUHAN PANGAN POKOK UNTUK PENANGGULANGAN BENCANA DI KABUPATEN SLEMAN

Background: Sleman district including proneness. Disasters cause suffering food insecurity, so that attempts to anticipate very necessary.The purpose of this research was to calculate how much of staple food such as rice and noodles as a source of energy required by the population especially those living in the area of Disaster Prone Areas (DPA) in Sleman in case catastrophic volcanic eruptions occur. Methods: This research was a quantitative descriptive research, calculate the amount of energy required by the population living in DPA using calculations of Recommended Daily Intake (RDI) average energy age group (kcal).The amount of energy sufficiency obtained than converted into food rice and instant noodles.The data collected was secondary data obtained from the relevant authorities such as the map of DPA, the amount and composition of the population by age and price of rice and instant noodles. Data was processed by Microsoft Excel and Nutri Survey Programs. Results and Conclusions: Recommended Dietary Intake (RDI) of resident in the area of Disaster Prone Areas (DPA) Sleman Regency were 339,964,150 kcal with the average achievement level of energy consumption is less category. If converted into staple food, it is equivalent to 49.7 tonnes of rice (Rp 374,250,000) and 2,137 boxes of instant noodles (Rp 102,624,000). Food reserves or budget must be provided for 5 days in anticipation of the needs of the population in the region when volcanic eruptions occur are as much as 248.5 tonnes of rice and 10,685 boxes of instant noodles, or equivalent to Rp 2,384,370,000. The number of staple food that has been provided by the government as much as 31 tons of rice, or 62.4% of the population requirements in a day. Keywords : Merapi, Food Disaster, Sleman District, PDA

Biogeographical determinants of pteridophytes and spermatophytes on oceanic archipelagos

Using the data from six oceanic archipelagos, we investigated the species richness patterns on islands for all natives, archipelagic endemics and single-island endemics of pteridophytes and spermatophytes. We tested the hypothesis that the descriptive ability of biogeographical factors for species is reduced as we move from native species, to archipelagic endemics and to single island endemics, because of the increasing importance of island ‘idiosyncrasies’ (i.e. unique features of each island shaping its biota, such as catastrophic volcanic eruptions, random colonization events, mega-landslides) in controlling the species richness of endemic species. This hypothesis was addressed using two approaches: (1) the island species–area relationships (ISARs), and (2) a multiple regression approach with variable selection based on permutation, to test the combined effects of island area with other biogeographical factors. Area was an effective predictor of species richness for all native species (R 2 = 0.568 and R 2 = 0.624 for pteridophytes and spermatophytes respectively), but its predictive capacity decreased for archipelagic endemics (R 2 = 0.261 and R 2 = 0.531) and single-island endemics (R 2 = 0.084 and R 2 = 0.438). The reduction of R 2 from all native species, to archipelagic endemics and to single-island endemics was attributed to the increasing effects of the ‘idiosyncrasies’ of each island. The predictive capacity of multiple regression models increased with respect to ISARs, ranging from 27.3% (for single-island endemic pteridophytes) to 83.3% (all native pteridophytes), and included three to five predictors. Island area remained the most important variable for spermatophytes but was less important for pteridophytes. For pteridophytes, elevation was the most important predictor for native species, while isolation-related variables were the most important predictors for archipelagic endemics and single-island endemics. Our results support the hypothesis that as we move from native, to archipelagic endemic and to single-island endemic species the predictive ability of models is reduced, indicating an increased effect of the ‘idiosyncratic’ character of islands.