Submarine Lava Deltas of the 2018 Eruption of Kīlauea Volcano

Hawaiian and other ocean island lava flows that reach the coastline can deposit significant volumes of lava in submarine deltas. The catastrophic collapse of these deltas represents one of the most significant, but least predictable, volcanic hazards at ocean islands. The volume of lava deposited below sea level in delta-forming eruptions and the mechanisms of delta construction and destruction are rarely documented. Here, we report on bathymetric surveys and ROV observations following the Kīlauea 2018 eruption that, along with a comparison to the deltas formed at Pu‘u ‘Ō‘ō over the past decade, provide new insight into delta formation. Bathymetric differencing reveals that the 2018 deltas contain more than half of the total volume of lava erupted. In addition, we find that the 2018 deltas are comprised largely of coarse-grained volcanic breccias and intact lava flows, which contrast with those at Pu‘u ‘Ō‘ō that contain a large fraction of fine-grained hyaloclastite. We attribute this difference to less efficient fragmentation of the 2018 ‘a‘ā flows leading to fragmentation by collapse rather than hydrovolcanic explosion. We suggest a mechanistic model where the characteristic grain size influences the form and stability of the delta with fine grain size deltas (Pu‘u ‘Ō‘ō) experiencing larger landslides with greater run-out supported by increased pore pressure and with coarse grain size deltas (Kīlauea 2018) experiencing smaller landslides that quickly stop as the pore pressure rapidly dissipates. This difference, if validated for other lava deltas, would provide a means to assess potential delta stability in future eruptions

Puffer: Pop-Up Flat Folding Explorer Robot

A repeatably reconfigurable robot, comprising at least two printed circuit board (PCB) rigid sections, at least one PCB flexible section coupled to the at least two PCB rigid sections, at least one wheel, hybrid wheel propeller, wheel and propeller, or hybrid wheel screw propeller rotatably coupled to at least one of the at least two PCB rigid sections and at least one actuator coupled to the at least two PCB rigid sections, wherein the at least one actuator folds and unfolds the repeatably reconfigurable robot

Alaska Earthquake Center Quarterly Technical Report October-December 2024

This series of technical quarterly reports from the Alaska Earthquake Center (AEC) includes detailed summaries and updates on Alaska seismicity, the AEC seismic network and stations, fieldwork, our online presence, public outreach, and lists publications and presentations by AEC staff. Multiple AEC staff members contributed to this report.1. Introduction 2. Seismicity 3. Alaska Geophysical Network 4. Data quality assurance 4.1 Seismic data 4.2 Environmental data 5. Real-time earthquake detection system 6. Computer systems 6.1 Computer resources 6.2 Waveform storage 6.3 Metadata 6.4 Software development 7. Fieldwork 7.1 October 7.2 November 7.3 December 8. Website, social media, and outreach 8.1 Website 8.2 X 8.3 Facebook 8.4 Instagram 8.5 LinkedIn 8.6 K-12 and community outreach 8.7 Workforce development 9. Publications and presentations 9.1 Publications 9.2 Public presentations 9.3 GI Geoscience lunch seminar talks 10. References Appendix A: Data availability for broadband stations from the AK network Appendix B: Gaps for broadband stations from the AK network Appendix C: 2025 strategic prioritie

Alaska Earthquake Center Quarterly Technical Report July-September 2024

This series of technical quarterly reports from the Alaska Earthquake Center (AEC) includes detailed summaries and updates on Alaska seismicity, the AEC seismic network and stations, fieldwork, our online presence, and lists publications and presentations by AEC staff. Multiple AEC staff members contribute to this report. It is issued within 1-2 months after the completion of each quarter Q1: January-March, Q2: April-June, Q3: July-September, and Q4: October-December. The first report was published for January-March, 2021.1. Introduction 2. Seismicity 3. Alaska Geophysical Network 4. Data quality assurance 4.1 Seismic data 4.2 Environmental data 5. Real-time earthquake detection system 6. Computer systems 6.1 Computer resources 6.2 Waveform storage 6.3 Metadata 6.4 Software development 7. Fieldwork 8. Social media and outreach 8.1 Website 8.2 X 8.3 Facebook 8.4 Instagram 8.5 LinkedIn 28 8.6 K–12 and community outreach 8.7 Workforce development 9. Publications and presentations 9.1 Publications 9.2 Public presentations 9.3 GI Geoscience lunch seminar talks 10. References Appendix A: Data availability for broadband stations from the AK network. Appendix B: Gaps for broadband stations from the AK network

Weak-intensity, basaltic, explosive volcanism : dynamics of Hawaiian fountains

Ph.D. University of Hawaii at Manoa 2013.Includes bibliographical references.Hawaiian fountains, typically occurring on basaltic volcanoes, are sustained, weakly-explosive jets of gas and juvenile ejecta. A broad range of Hawaiian fountaining styles occurred during twelve episodes of the Mauna Ulu eruption on Kīlauea between May and December 1969. The western episode 1 fissure system is currently well exposed, providing an exclusive opportunity to study processes of low-intensity fissure fountains. Episode 1 fountains occurred along a 5 km long fissure system that exploited the eastern-most kilometer of the Ko'ai fault system. A low, near-continuous, spatter rampart is present on the northern upwind and upslope side of the fissure. Most pyroclastic products, however, fell downwind to the south and little was preserved because of two processes: 1) incorporation of proximal spatter in rheomorphic lava flows 10--20 meters from the vents, and 2) downslope transport of cooler spatter falling on top of these flows >20 meters from vent. There is a clear 'lava-shed' delineation between lava that drained back into the fissure and lava that continued flowing into the flowfield. Vents range in surface geometry from linear--circular, with superimposed irregularity and sinuosity, and range from straight-sided--flaring cross-sectional geometries. Irregularity results from joints in the pre-existing wall rock. Sinuosity results from the local stress field. Geometry of non-flared vents could indicate the true geometry of the dike. Flared vents likely formed through mechanical erosion and thermo-mechanical abrasion. Vent positions along the fissure likely resulted from flow focusing. Uniquely, these vents drained and remain unobstructed (some >100 m depth), despite subsequent nearby eruptive activity. Three vents were imaged ≤16 m in depth at <4 cm resolution with tripod-mounted LiDAR. Textural analyses of pyroclasts from eruptive episodes 2--12 show three distinct degassing and outgassing paths: 1) rapid degassing and quenching with minimal outgassing, 2) prolonged degassing and outgassing, and 3) rapid degassing and quenching on pyroclasts' rims with prolonged internal bubble coalesce. Contrasting patterns of shallow degassing and outgassing were the dominant control driving Hawaiian fountain behavior and variability, and are probably the dominant control for many other Hawaiian-style eruptions

Submarine lava deltas of the 2018 eruption of Kīlauea volcano

AbstractHawaiian and other ocean island lava flows that reach the coastline can deposit significant volumes of lava in submarine deltas. The catastrophic collapse of these deltas represents one of the most significant, but least predictable, volcanic hazards at ocean islands. The volume of lava deposited below sea level in delta-forming eruptions and the mechanisms of delta construction and destruction are rarely documented. Here, we report on bathymetric surveys and ROV observations following the Kīlauea 2018 eruption that, along with a comparison to the deltas formed at Pu‘u ‘Ō‘ō over the past decade, provide new insight into delta formation. Bathymetric differencing reveals that the 2018 deltas contain more than half of the total volume of lava erupted. In addition, we find that the 2018 deltas are comprised largely of coarse-grained volcanic breccias and intact lava flows, which contrast with those at Pu‘u ‘Ō‘ō that contain a large fraction of fine-grained hyaloclastite. We attribute this difference to less efficient fragmentation of the 2018 ‘a‘ā flows leading to fragmentation by collapse rather than hydrovolcanic explosion. We suggest a mechanistic model where the characteristic grain size influences the form and stability of the delta with fine grain size deltas (Pu‘u ‘Ō‘ō) experiencing larger landslides with greater run-out supported by increased pore pressure and with coarse grain size deltas (Kīlauea 2018) experiencing smaller landslides that quickly stop as the pore pressure rapidly dissipates. This difference, if validated for other lava deltas, would provide a means to assess potential delta stability in future eruptions.</jats:p

Tracking an Active Eruption for Insight into the Dynamics Behind Planetary Volcanic Features

No abstract availabl

Volcanic Jet Noise from the Kilauea Fissure 8 Lava Fountain

&amp;lt;p&amp;gt;Seismic and acoustic signals are important for remote real time and post-eruption analysis of volcanic eruptions. To properly interpret these signals it is critical to connect their characteristics with eruption parameters. In this study, we present an analysis of the infrasound emissions by the sustained lava fountain at Fissure 8 during the 2018 eruption of Kilauea Volcano, Hawaii. This eruption was one of the largest and most destructive events in Hawaii&amp;amp;#8217;s historic times. Large (35.5 km2) lava flows covered much of the Lower East Rift Zone (LERZ) and destroyed property and infrastructure. This activity was dominated by high lava effusion rates at Fissure 8 and lava fountains up to 80 m tall. The energetic output of gas and lava produced sustained, broadband acoustic waves which were recorded by a four-element infrasound array deployed 0.6 km northwest of the fountain. The spectrum of the infrasound is similar to that of man-made jets and is termed volcanic jet noise. We compare the spectrum of the recorded infrasound signal with models developed for man-made jets such as rockets and jet engines. These models predict different spectral shapes for fine scale turbulence (FST), produced by incoherent movement of the gases, and large scale turbulence (LST), produced by coherent instability waves. The dominance of one or the other turbulent noise source is highly directional. We compare the infrasonic signals with observations of fountain properties, such as pyroclast velocity and height, to help understand the jet noise signals and determine quantitative fountain properties from the infrasound. The results of this work will contribute to the understanding of the physics of lava fountain sound generation, its dependence on eruption parameters, and ultimately provide a tool for rapid assessment of eruption style and dynamics.&amp;lt;/p&amp;gt; </jats:p

The tangled tale of Kīlauea’s 2018 eruption as told by geochemical monitoring

Caldera collapse and flank eruption Real-time monitoring of volcanic eruptions involving caldera-forming events are rare (see the Perspective by Sigmundsson). Anderson et al. used several types of geophysical observations to track the caldera-forming collapse at the top of Kīlauea Volcano, Hawai'i, during the 2018 eruption. Gansecki et al. used near–real-time lava composition analysis to determine when magma shifted from highly viscous, slow-moving lava to low-viscosity, fast-moving lava. Patrick et al. used a range of geophysical tools to connect processes at the summit to lava rates coming out of far-away fissures. Together, the three studies improve caldera-collapse models and may help improve real-time hazard responses. Science , this issue p. eaaz0147 , p. eaay9070 ; p. eaaz1822 ; see also p. 1200 </jats:p