John Townend
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Temporal Evolution of Seismicity in the Central Southern Alps, New Zealand: Evidence for Rainfall‐Triggered Seismicity Open
Understanding the conditions and mechanisms that produce earthquakes is of high scientific relevance. The central Southern Alps/Kā Tiritiri o te Moana of New Zealand is an active orogen that offers a unique opportunity to study the process…
Using citizen science Raspberry Shake seismometers to enhance earthquake location and characterization: a case study from Wellington, New Zealand Open
The recent development of low-cost citizen seismometers has opened new avenues for earthquake analysis. We explore the integration of Raspberry Shake citizen seismometers with the national GeoNet seismic network to improve the precision of…
Unsupervised Coherent Noise Removal From Seismological Distributed Acoustic Sensing Data Open
Recent advances in sensing technologies, particularly Distributed Acoustic Sensing (DAS), have significantly improved the collection and analysis of seismological data. DAS is a powerful method for detecting vibrations from various sources…
View article: Low‐Frequency Earthquakes Downdip of Deep Slow Slip Beneath the North Island of New Zealand
Low‐Frequency Earthquakes Downdip of Deep Slow Slip Beneath the North Island of New Zealand Open
We report the first catalog of low‐frequency earthquakes in the Hikurangi subduction zone, located beneath the Kaimanawa Range of the North Island at 50 km depth, downdip of regularly recurring (every 4–5 years) deep M7 slow slip events. T…
Evidence From Intermediate‐Depth Earthquakes of Slab‐Derived Fluids Beneath the Taupō Volcanic Zone Open
Ahi Tupua, the central section of the Taupō Volcanic Zone in the central North Island of New Zealand, encompasses Taupō and Ōkataina calderas and has been the most frequently active and productive silicic magma system worldwide during the …
The Response of Taupō Volcano to the M7.8 Kaikōura Earthquake Open
Several studies suggest that large earthquakes ( M > 7.0) can act as external triggers of volcanic unrest, and even eruption. This triggering is attributed to either ground shaking (dynamic stresses) or to permanent ground deformation (ass…
View article: Inferred source models for Alpine Fault Earthquake Scenarios and influence on seismic hazard.
Inferred source models for Alpine Fault Earthquake Scenarios and influence on seismic hazard. Open
As part of the Southern Alps Long Skinny Array (SALSA) project, ~35+ seismometers have been deployed with 10–12 km spacing along a 450 km-long section of the Alpine Fault. SALSA is focused on determining the ground motions likely to be pro…
View article: Parametric Testing of EQTransformer’s Performance against a High-Quality, Manually Picked Catalog for Reliable and Accurate Seismic Phase Picking
Parametric Testing of EQTransformer’s Performance against a High-Quality, Manually Picked Catalog for Reliable and Accurate Seismic Phase Picking Open
This study evaluates EQTransformer, a deep learning model, for earthquake detection and phase picking using seismic data from the Southern Alps, New Zealand. Using a robust, independent dataset containing more than 85,000 manual picks from…
View article: Codes and catalogs for: Parametric testing of EQTransformer's performance against a high-quality, manually-picked catalog for reliable and accurate seismic phase picking
Codes and catalogs for: Parametric testing of EQTransformer's performance against a high-quality, manually-picked catalog for reliable and accurate seismic phase picking Open
Codes and Catalogs for: "Parametric Testing of EQTransformer's Performance Against a High-Quality, Manually-Picked Catalog for Reliable and Accurate Seismic Phase Picking." Codes: overlap_check.py: This script tests the overlap parameter o…
View article: Codes and catalogs for: Parametric testing of EQTransformer's performance against a high-quality, manually-picked catalog for reliable and accurate seismic phase picking
Codes and catalogs for: Parametric testing of EQTransformer's performance against a high-quality, manually-picked catalog for reliable and accurate seismic phase picking Open
Codes and Catalogs for: "Parametric Testing of EQTransformer's Performance Against a High-Quality, Manually-Picked Catalog for Reliable and Accurate Seismic Phase Picking." Codes: overlap_check.py: This script tests the overlap parameter o…
Ambient seismic noise tomography of the Kingdom of Saudi Arabia Open
First posted December 29, 2023 For additional information, contact: Volcano Science Center - Menlo ParkU.S. Geological Survey345 Middlefield Road, MS 910Menlo Park, CA 94025Contact Pubs Warehouse Harrat Rahat is a Cenozoic volcanic field i…
View article: Earthquakes and Seismic Hazard in Southern New Caledonia, Southwest Pacific
Earthquakes and Seismic Hazard in Southern New Caledonia, Southwest Pacific Open
We use 12 temporary and 9 permanent broadband seismometers that were operating for ∼400 days from October 2018 to November 2019 to generate the first published earthquake catalog and local magnitude function for southern New Caledonia (SNC…
The 2001 Taupō Fault Belt Seismicity as Evidence of Magma‐Tectonic Interaction at Taupō Volcano Open
The Taupō Volcanic Zone (TVZ) is the southern extent of the Tonga‐Kermadec volcanic arc and encompasses the Taupō Rift, with the two structures accommodating extension through the central North Island of New Zealand via magmatic and tecton…
Earthquake catalogue for the Taupō Fault Belt, New Zealand, 2001 Open
This dataset contains the earthquake catalogue and focal mechanism data associated with the manuscript "The 2001 Taupō Fault Belt sequence as evidence for magma-tectonic interaction at Taupō Volcano" by McGregor et al. If you use this date…
Earthquake catalogue for the Taupō Fault Belt, New Zealand, 2001 Open
This dataset contains the earthquake catalogue and focal mechanism data associated with the manuscript "The 2001 Taupō Fault Belt sequence as evidence for magma-tectonic interaction at Taupō Volcano" by McGregor et al. If you use this date…
View article: Assessing damage pattern at depth near the Alpine Fault, New Zealand
Assessing damage pattern at depth near the Alpine Fault, New Zealand Open
The Alpine Fault is the principal component of the plate boundary through the South Island of New Zealand, separating the Pacific and Indo-Australian Plates. It is recognised internationally as an important site for studying earthquake phy…
Low-frequency earthquakes accompany deep slow slip beneath the North Island of New Zealand Open
Slow slip events have previously been observed along the Hikurangi subduction zone beneath the North Island of New Zealand. These slow slip episodes occur both on the shallow plate interface ( 30km depth). We present the first catalog of l…
Catalog of low frequency earthquake beneath the Kaimanawa ranges, North Island of New Zealand Open
lfe_locations.csv contains the information relative to the 77 LFE candidates: 1. Template name: name 2. NonLinLoc location, error ellipsoid and uncertainties: lat, lon, depth, az1, dip1, len1, az2, dip2, len2, len3, rms, elat, elon, edepth…
Catalog of low frequency earthquake beneath the Kaimanawa ranges, North Island of New Zealand Open
lfe_locations.csv contains the information relative to the 77 LFE candidates: 1. Template name: name 2. NonLinLoc location, error ellipsoid and uncertainties: lat, lon, depth, az1, dip1, len1, az2, dip2, len2, len3, rms, elat, elon, edepth…
Strong Upper‐Plate Heterogeneity at the Hikurangi Subduction Margin (North Island, New Zealand) Imaged by Adjoint Tomography Open
We use earthquake‐based adjoint tomography to invert for three‐dimensional structure of the North Island, New Zealand, and the adjacent Hikurangi subduction zone. The study area, having a shallow depth to the plate interface below the Nort…
3D Active Source Seismic Imaging of the Alpine Fault Zone and the Whataroa Glacial Valley in New Zealand Open
The Alpine Fault zone in New Zealand marks a major transpressional plate boundary that is late in its typical earthquake cycle. Understanding the subsurface structures is crucial to understand the tectonic processes taking place. A unique …
Strong upper-plate heterogeneity at the Hikurangi subduction margin (North Island, New Zealand) imaged by adjoint tomography Open
We use earthquake-based adjoint tomography to invert for three-dimensional structure of the North Island, New Zealand, and the adjacent Hikurangi subduction zone. The study area, having a shallow depth to the plate interface below the Nort…
Evidence for deeply-subducted lower-plate seamounts at the Hikurangi subduction margin: implications for seismic and aseismic behavior Open
Seamounts are found at many subduction zones and act as seafloor heterogeneities that affect slip behavior on megathrusts. At the Hikurangi subduction zone offshore the North Island, New Zealand, seamounts have been identified on the incom…
Illuminating the Pre‐, Co‐, and Post‐Seismic Phases of the 2016 M7.8 Kaikōura Earthquake With 10 Years of Seismicity Open
The 2016 M7.8 Kaikōura earthquake is one of the most complex earthquakes in recorded history, with significant rupture of at least 21 crustal faults. Using a matched‐filter detection routine, precise cross‐correlation pick corrections, and…
Earthquake Catalogue for: Illuminating the pre-, co-, and post-seismic phases of the 2016 M7.8 Kaikoura earthquake with 10 years of seismicity Open
0.2: Correction This version corrects the original dataset which had some incorrect focal mechanisms. These mechanisms had incorrect rakes as a result of an error in the uncertainty calculation algorithm. The remainder of the catalogue is …
Earthquake Catalogue for: Illuminating the pre-, co-, and post-seismic phases of the 2016 M7.8 Kaikoura earthquake with 10 years of seismicity Open
0.2: Correction This version corrects the original dataset which had some incorrect focal mechanisms. These mechanisms had incorrect rakes as a result of an error in the uncertainty calculation algorithm. The remainder of the catalogue is …
Earthquake Catalogue for: Illuminating the pre-, co-, and post-seismic phases of the 2016 M7.8 Kaikoura earthquake with 10 years of seismicity Open
Earthquake catalogue generated around the rupture area of the 2016 M7.8 Kaikoura earthquake. For a full description see the associated paper submitted to JGR 2021. The catalogue is here in two forms: A QuakeML file with all picks, magnitud…
Earthquake Catalogue for: Illuminating the pre-, co-, and post-seismic phases of the 2016 M7.8 Kaikoura earthquake with 10 years of seismicity Open
Earthquake catalogue generated around the rupture area of the 2016 M7.8 Kaikoura earthquake. For a full description see the associated paper submitted to JGR 2021. The catalogue is here in two forms: A QuakeML file with all picks, magnitud…