Seismic constraints on caldera dynamics from the 2015 Axial Seamount eruption

Wilcock, William S. D.; Tolstoy, M.; Waldhauser, F.; García, C.; Tan, Yen Joe; Bohnenstiehl, D. R.; Caplan‐Auerbach, J.; Dziak, Robert P.; Arnulf, A. F.; Mann, Michael Everett

doi:10.1126/science.aah5563

Cited by 102 publications

(234 citation statements)

References 38 publications

Supporting

Mentioning

216

Contrasting

Unclassified

Order By: Relevance

“…Evolution of travel time RMS residuals associated with the LOTOS joint inversion procedure. (a) RMS residuals for P and S waves using the 1‐D V P and Vs models (from Wilcock et al, ) and evolution for the four iterations using the 3‐D V P and Vs models (solid and dashed lines, respectively). RMS residuals are stable after two iterations and fully converge after four iterations.…”

Section: Resultsmentioning

confidence: 99%

A Joint Inversion for Three‐dimensional P and S Wave Velocity Structure and Earthquake Locations Beneath Axial Seamount

et al. 2019

Self Cite

View full text Add to dashboard Cite

Axial Seamount is a prominent volcano located at the intersection of the Juan de Fuca Ridge and the Cobb‐Eickelberg hot spot in the northeast Pacific Ocean that has erupted in 1998, 2011, and 2015. The 2015 eruption was recorded by a seven‐station seismic network in the southern part of the summit caldera that forms part of the Ocean Observatories Initiative Cabled Array. We utilize a data set of ~3,900 well‐recorded earthquakes from January 2015 to February 2017 and a three‐dimensional P wave velocity model obtained previously from active source data to conduct a joint inversion for three‐dimensional P and S wave velocities and hypocentral parameters. The resulting velocity models are used to relocate >76,000 earthquakes with ≥10 arrival times. The velocity models reveal a low‐velocity anomaly in the center of the southern caldera at depths less than ~2 km, which corresponds to the top of the magma chamber and is interpreted as a region that is intensely fractured by the cyclical deformation of the caldera. High velocities around the caldera rim are likely due to consolidated undeformed lava flows. Low VP/VS in the southern caldera is consistent with the presence of hydrothermal vapor. Low S wave velocities and high VP/VS in the northern caldera may indicate a region dominated by thin cracks caused by dike injection. The relocated earthquakes delineate outward‐dipping ring faults more clearly than previous studies and image a subvertical inward‐dipping fault within the network that connects to the east caldera wall and eruptive fissures.

show abstract

Section: Resultsmentioning

confidence: 99%

A Joint Inversion for Three‐dimensional P and S Wave Velocity Structure and Earthquake Locations Beneath Axial Seamount

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Volcanic unrest in 2015 at Axial Seamount began with an increase in seismicity starting at ~04:20 on 24 April (all times in Coordinated Universal Time (UTC)) [ Wilcock et al ., ], followed by the onset of large tilts and rapid deflation in the caldera at ~06:00 [ Nooner and Chadwick , ]. Earthquake epicenters during the first 24 h clustered along the eastern edge of the caldera [ Wilcock et al ., ]. Hydroacoustic (waterborne) impulsive signals originating from north of the caldera commenced at ~9:00 and lasted for several weeks [ Wilcock et al ., ].…”

Section: Mapping Of the 2015 Lava Flowsmentioning

confidence: 99%

“…Earthquake epicenters during the first 24 h clustered along the eastern edge of the caldera [ Wilcock et al ., ]. Hydroacoustic (waterborne) impulsive signals originating from north of the caldera commenced at ~9:00 and lasted for several weeks [ Wilcock et al ., ]. The source locations of the hydroacoustic signals prompted a bathymetric resurvey of the NRZ and NE summit during the first posteruption expedition to Axial (TN326 in July 2015) using the EM302 multibeam sonar system on board the R/V Thompson [ Kelley et al ., ].…”

Section: Mapping Of the 2015 Lava Flowsmentioning

confidence: 99%

“…This larger erupted volume and the dramatically decreased recurrence interval (13 years between 1998 and 2011 versus 4 years between 2011 and 2015) are evidence of an increased magma supply at Axial Seamount, consistent with an increased rate of inflation since 2011 detected by geodetic monitoring [ Nooner and Chadwick , ]. The coeruption seismicity [ Wilcock et al ., ] and the lava chemistry (described below) indicate that magma first intruded from the summit reservoir as a dike along the eastern edge of the caldera and then propagated northward into the NRZ after ~07:00 on 24 April (Figure ); thus, the lava flows likely erupted from south to north.…”

Section: Mapping Of the 2015 Lava Flowsmentioning

confidence: 99%

See 1 more Smart Citation

Voluminous eruption from a zoned magma body after an increase in supply rate at Axial Seamount

Chadwick

Paduan

Clague

et al. 2016

Geophysical Research Letters

153

View full text Add to dashboard Cite

Axial Seamount is the best monitored submarine volcano in the world, providing an exceptional window into the dynamic interactions between magma storage, transport, and eruption processes in a mid‐ocean ridge setting. An eruption in April 2015 produced the largest volume of erupted lava since monitoring and mapping began in the mid‐1980s after the shortest repose time, due to a recent increase in magma supply. The higher rate of magma replenishment since 2011 resulted in the eruption of the most mafic lava in the last 500–600 years. Eruptive fissures at the volcano summit produced pyroclastic ash that was deposited over an area of at least 8 km2. A systematic spatial distribution of compositions is consistent with a single dike tapping different parts of a thermally and chemically zoned magma reservoir that can be directly related to previous multichannel seismic‐imaging results.

show abstract

“…The area extending between 9°46′ and 9°56′N, underlain by three well‐defined AML segments (Carbotte et al, ), coincides with the region of two documented eruptions in 1991–1992 (Haymon et al, ) and 2005–2006 (Figure b) (Tolstoy et al, ). It represents one of the most volcanically active zones along the MOR system, if we exclude the portions of direct ridge‐hot spot interaction, for example, Axial Segment along the Juan de Fuca Ridge, influenced by the Cobb hot spot (e.g., Chadwick et al, ; Wilcock et al, ). In addition, an abundance of hydrothermal venting activity has been taking place in this area (Figure b) (Fornari et al, , ; Haymon et al, ; Haymon & White, ; Sohn et al, , ).…”

Section: Introductionmentioning

confidence: 99%

Seismic Signatures of Hydrothermal Pathways Along the East Pacific Rise Between 9°16′ and 9°56′N

et al. 2017

View full text Add to dashboard Cite

We apply wave equation‐based techniques to 2‐D seismic data to characterize the nature of zero‐age upper crust at the East Pacific Rise from 9°16′ to 9°56′N. The final velocity model reveals a number of low‐velocity anomalies, complex in shape, extending down to ~1 km below the seafloor. We attribute them to the presence of hydrothermal flow. Depending on their spatial correlation with the previously identified tectonic discontinuities in bathymetry and presence of venting, we classify them as downgoing and upgoing pathways, respectively. This distinction is not always clear; within the third‐order discontinuities at 9°20′ and 9°37′N, both pathways may be present. The region north of 9°44′N, known for its magmatic robustness and volcanic activity, is represented by five low‐velocity perturbations. Three of these anomalies are spatially correlated with the fourth‐order discontinuities and attributed to the presence of the on‐axis recharge zones. The remaining two anomalies underlie two vent clusters, marked as hydrothermally active sites after the last documented eruption event. These velocity anomalies can be thus identified as the up‐flow pathways or at least their remnants. By comparing our results to the available interdisciplinary data sets, we show that the interaction between the tectono‐magmatic and hydrothermal processes is not straightforward due to different timescales at which they operate. However, for developing, maintaining, and driving vigorous, high‐temperature hydrothermal flow, the high crustal permeability and high thermal regime must coexist in time and space.

show abstract

Seismic constraints on caldera dynamics from the 2015 Axial Seamount eruption

Cited by 102 publications

References 38 publications

A Joint Inversion for Three‐dimensional P and S Wave Velocity Structure and Earthquake Locations Beneath Axial Seamount

A Joint Inversion for Three‐dimensional P and S Wave Velocity Structure and Earthquake Locations Beneath Axial Seamount

Voluminous eruption from a zoned magma body after an increase in supply rate at Axial Seamount

Seismic Signatures of Hydrothermal Pathways Along the East Pacific Rise Between 9°16′ and 9°56′N

Contact Info

Product

Resources

About