The eruption of the Anak Krakatoa volcano (Indonesia) in December 2018 produced a destructive tsunami with maximum runup 13 m killing 437 people. Since occurrence this rare tsunami, it has been challenge as how to model and reconstruct network coastal observations. Here, we apply combination qualitative physical modeling wavelet analyses well numerical propose source model. Physical flank collapse showed that initial wave mostly involves pure-elevation wave. We identified period 6.3–8.9 min...

Abstract On 8 October 2023, mysterious tsunamis with a maximum wave height of 60 cm were observed in Izu Islands and southwestern Japan, although only seismic events body‐wave magnitudes m b 4–5 have been documented to the west Sofugan volcano. To investigate source process, we analyze tsunami waveforms recorded by an array network ocean bottom pressure gauges. Stacked gauge records suggest recurrent arrivals multiple trains. Deconvolution stacked from earlier event revealed over 10 that...

Abstract Ocean-bottom pressure gauges of wide and dense ocean-bottom observation networks around Japan, S-net DONET, observed ocean waves caused by the Tonga eruption that started at approximately 13:00 JST (UTC + 0900) on January 15, 2022. We scrutinized waveform records arriving to evaluate their nature found two significant disturbances between 20:00 21:00 after 22:00. The first disturbance with a positive-polarity pulse dominated long-period components (1000–3000 s) arrived DONET...

Abstract The main cause of tsunamis is large subduction zone earthquakes with seismic magnitudes M w > 7, but submarine volcanic processes can also generate tsunamis. At the Sumisu caldera in Izu–Bonin arc, moderate‐sized < 6 occur almost once a decade and meter‐scale source mechanism poorly understood. Here we use tsunami data from recent 2015 event to show that abrupt uplift caldera, brittle rupture ring fault system due overpressure its magma reservoir, caused earthquake tsunami....

Abstract Two submarine earthquakes ( M w 5.8) occurred near volcanic islands, Curtis and Cheeseman, in the Kermadec Arc 2009 2017. Following both earthquakes, similar tsunamis with wave heights of about a meter, larger than expected from their moderate seismic magnitudes, were observed by coastal tide gauges. We investigate source mechanism for analyzing tsunami data 2017 event. Tsunami waveform analysis indicates that earthquake uplifted submerged caldera around islands. Combined suggests...

Abstract On 8 October 2023 UTC, significant tsunamis were observed around Japan without any major tsunamigenic earthquake, associated with a series of 14 successive minor earthquakes ( m b = 4.5–5.4) near Sofugan in the Izu‐Bonin Islands. To examine cause this tsunami, we estimated horizontal locations tsunami source and temporal history seafloor displacement, using data recorded by ocean‐bottom pressure gauges >∼600 km away. Our results showed main was an uplift located at caldera‐like...

Abstract Moderate earthquakes ( M w > 5) with moment tensors (MTs) dominated by a vertical compensated‐linear‐vector‐dipole (vertical‐CLVD) component are often generated dip slip along curved ring‐fault system at active volcanoes. However, relating their MTs to parameters has been proved difficult. The objective of this study is find robust way estimating some based on MT solutions obtained from long‐period seismic records. We first model the idealized ring‐faulting and show that...

Abstract Although most tsunamis are generated by the sea‐bottom deformation caused earthquakes, some excited sea‐surface pressure changes. This study theoretically investigated changes and derived solutions in three‐dimensional (3‐D) space, whereas past studies employed two‐dimensional equations. Using solutions, we simulated visualized tsunami generation a growing change. Negative change made sea surface uplifted inside source region negative leading waves were radiated from region. We also...

Abstract This study reports an ocean‐bottom pressure gauge (OBP) network, S‐net, which captured meteotsunamis with amplitudes as small a few cm, and investigates its validity limitation for meteotsunami research studies through data analyses numerical simulations. On July 1, 2020, S‐net recorded tsunami‐like signals, although no earthquake was reported. These waves, propagating northward velocity of ∼110 m/s, were explained by atmospheric low maximum amplitude −0.5 ± 0.1 hPa moving...

Anomalously large tsunamis generated by a submarine volcanic earthquake were recorded an ocean bottom pressure gauge array.

Abstract Abnormal volcanic earthquakes occurring near the island of Torishima, south Japan, sometimes generate relatively larger tsunamis compared to seismic magnitudes. They have a non‐double‐couple focal mechanism known as compensated linear vector dipole. The unusual earthquake source poses difficulties in traditional tsunami forecasting method based on parameters. Tsunami data assimilation, forecast using offshore observation and numerical model, avoids complexities uncertainties...

Abstract We observed the activity of long‐period tremors (LPTs) with a period ~15 s at Aso volcano, Japan, during 3 year including 2014 eruptions. The number LPTs detected systematically increased months before Strombolian LPT can be divided into five stages based on rapid changes in maximum amplitude. amplitude‐frequency relation follows an exponential distribution each stage eruptions, different characteristic amplitudes for stage, indicating that scale source property changed stages....

Abstract Characterizing the large M4.7+ seismic events during 2018 Kīlauea eruption is important to understand complex subsurface deformation at summit. The first 12 (May 17–May 26) are associated with long‐duration signals and remaining 50 29–August 2) accompanied by large‐scale caldera collapses. Resolving source location mechanism challenging because of shallow depth, significant nondouble‐couple components, velocity structure. We demonstrate that combining multiple geophysical data from...

SUMMARY Tsunamis are often modelled as surface gravity waves of incompressible homogenous water propagating over a rigid seafloor. Previous studies have noted that when computing long-period tsunamis travelling at trans-oceanic distances with dominant periods thousands seconds, we need to consider four factors not included in the wave theory: compressibility seawater, density stratification oceans, elasticity Earth and gravitational potential change associated tsunami motion. However, their...

Abstract Submarine volcano monitoring is vital for assessing volcanic hazards but challenging in remote and inaccessible environments. In the vicinity of Kita‐Ioto Island, south Japan, unusual M ∼ 5 non‐double‐couple earthquakes exhibited quasi‐regular recurrence near a submarine caldera. Following 2008 2015, distant ocean bottom pressure sensor recorded distinct tsunami signals. this study, we aim to find source model tsunami‐generating earthquake quantify pre‐seismic magma overpressure...

Abstract An unexpected major tsunami from the region near Sofu Seamount was observed on 8 October 2023. is located approximately 600 km coast of Japan. Due to far epicentral distances and successive occurrence seismic events, conventional analysis reveal accompanying sequence cannot work well. We investigated high‐frequency teleseismic P regional T waves during tsunamigenic events Seamount. Envelope shapes were similar, indicating that ‐wave envelopes also reflected source properties...

On 8 October 2023 UTC, significant tsunamis were observed around Japan without any major tsunamigenic earthquake, associated with a series of 14 successive minor earthquakes (mb = 4.5–5.4) near Sofugan in the Izu-Bonin islands. To examine cause this tsunami, we estimated horizontal locations tsunami source and temporal history seafloor displacement, using data recorded by ocean-bottom pressure gauges > ~600 km away. Our results showed main was an uplift located at caldera-like bathymetric...

On 9 October 2023 (JST), mysterious tsunamis with a maximum wave height of 60 cm were observed in Izu Islands and southwestern Japan, although only seismic events body-wave magnitudes mb 4–5 have been documented the southwest Torishima Island. To investigate source process, we analyze tsunami waveforms recorded by an array network ocean-bottom pressure gauges. A stacked waveform 16 records suggests recurrent arrivals multiple trains. Deconvolution from first event revealed over 10 that...

An unexpected major tsunami from the region near Sofu Seamount was observed on 8 October 2023. The is located approximately 600 km coast of Japan. Due to far epicentral distances and successive occurrence seismic events, conventional analysis reveal accompanying sequence cannot work well. We investigated high-frequency teleseismic P regional T waves during tsunamigenic events Seamount. Envelope shapes were similar, indicating that T-wave envelopes also reflected source properties sequence....

Abstract Submarine calderas with active magma supply have recently been identified as potential sources of volcanic tsunamis due to sudden meter‐scale uplift by trapdoor faulting, occurring every few years a decade. These uplifts are seismically recorded non‐double‐couple earthquakes magnitudes M > 5. Kita‐Ioto Caldera, submarine caldera in the Izu‐Bonin arc, caused such 2–5 years. Our previous study (Sandanbata & Saito, 2024, https://doi.org/10.1029/2023jb027917 ) analyzed data from...

Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Journal of Geophysical Research - Oceans. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Meteorological tsunami generation due sea-surface pressure change: Three-dimensional theory synthetics ocean-bottom...