Andrew Bell
YOU?
Author Swipe
View article: Magma Ascent and Accumulation Drives Surface Deformation and Ring Fault Seismicity Preceding the 2024 Eruption of Fernandina Volcano, Galápagos Islands
Magma Ascent and Accumulation Drives Surface Deformation and Ring Fault Seismicity Preceding the 2024 Eruption of Fernandina Volcano, Galápagos Islands Open
At caldera volcanoes, ring faults can play a key role in controlling the dynamics of unrest and patterns of associated surface deformation and seismicity. Here we show that the March 2024 eruption of Fernandina volcano was preceded by a 2.…
View article: Lava Tube System Development Defined by Multispectral Imaging and InSAR: The Case of the 2024 Eruption of Fernandina Volcano (Galápagos)
Lava Tube System Development Defined by Multispectral Imaging and InSAR: The Case of the 2024 Eruption of Fernandina Volcano (Galápagos) Open
Lava tubes are subsurface conduits within a lava flow that feed its advance. Lava tube detection is important to understand lava flow dynamics and to mitigate geohazards. Here we use InSAR‐derived surface motion data, in combination with s…
View article: Comment to Shreve and Delgado (2023)—“ <i>Trapdoor Fault Activation</i> : <i>A Step Toward Caldera Collapse at Sierra Negra</i> , <i>Galapagos</i> , <i>Ecuador</i> ”
Comment to Shreve and Delgado (2023)—“ <i>Trapdoor Fault Activation</i> : <i>A Step Toward Caldera Collapse at Sierra Negra</i> , <i>Galapagos</i> , <i>Ecuador</i> ” Open
In their article entitled “ Trapdoor Fault Activation : A Step Toward Caldera Collapse at Sierra Negra , Galapagos , Ecuador ” Shreve and Delgado (2023, https://doi.org/10.1029/2023jb026437 ) examine co‐eruptive deformation during the 2018…
View article: Estimating the impact of the Russian invasion on the displacement of graduating high school students in Ukraine
Estimating the impact of the Russian invasion on the displacement of graduating high school students in Ukraine Open
On 24 February 2022, Russia began a full-scale invasion of Ukraine. The war has dramatically impacted every area of life in Ukraine, including education. In this paper, we curate a uniquely comprehensive dataset of standardized exam outcom…
View article: Loading of a porous rock with constant micro-seismic event rate suppresses seismicity and promotes subcritical failure
Loading of a porous rock with constant micro-seismic event rate suppresses seismicity and promotes subcritical failure Open
Catastrophic failure is the end result of progressive localisation of damage creating brittle failure on a variety of system scales in the Earth. However, the factors controlling this evolution, and the relationship between deformation and…
View article: Multi-Sensor Remote Sensing Captures Geometry and Slow-to-Fast Sliding Transition of the 2017 Mud Creek landslide
Multi-Sensor Remote Sensing Captures Geometry and Slow-to-Fast Sliding Transition of the 2017 Mud Creek landslide Open
Landslides triggered by rainfall pose a significant hazard worldwide. Despite advances in landslide monitoring, predicting their size, timing, and location remains a major challenge. We revisit the 2017 Mud Creek landslide in California us…
View article: Infrared Satellite Detection Limits for Monitoring Atmospheric Ammonia
Infrared Satellite Detection Limits for Monitoring Atmospheric Ammonia Open
This study investigates single pixel nadir viewing detection limit of atmospheric ammonia for a range of area flux mapping satellite infrared sensor spectral resolutions (0.05–2.0 cm−1) and measurement noise levels. The detection level of …
View article: Craters of habit: Patterns of deformation in the western Galápagos
Craters of habit: Patterns of deformation in the western Galápagos Open
The western Galápagos islands of Fernandina and Isabela comprise six active volcanoes that have deformed since first observed by satellite radar in the early 1990s. We analyse new (2015–2022) displacement time series at Alcedo, Cerro Azul,…
View article: Understanding unrest and dynamic triggering processes on Sierra Negra, Gal&#225;pagos Islands.
Understanding unrest and dynamic triggering processes on Sierra Negra, Galápagos Islands. Open
Dynamic earthquake triggering refers to the phenomenon where local seismic activity is induced by dynamic stress disturbances, originating from teleseismic earthquakes. An understanding of dynamic triggering on volcanoes offers a window in…
View article: Temporal enrichment of the seismic record of the 2018 eruption at Sierra Negra using deep neural networks
Temporal enrichment of the seismic record of the 2018 eruption at Sierra Negra using deep neural networks Open
The 2018 eruption at Sierra Negra volcano, Galapagos Islands, was accompanied by 8.5 metres of caldera subsidence and intense seismicity, resulting from deflation of a shallow sill-like magma reservoir at ~2 km depth. High-precision hypoce…
View article: Patterns of deformation and connectivity at Western Gal&#225;pagos Volcanoes
Patterns of deformation and connectivity at Western Galápagos Volcanoes Open
The Western Galápagos volcanoes of Alcedo, Cerro Azul, Darwin, Fernandina, Sierra Negra, and Wolf have exceptionally high rates of eruption and unrest.  Deformation rates measured using Interferometric Synthetic Aperture Radar ar…
View article: Numerical modelling of earthquake induced stress changes and dike migration preceding the 2018 eruption of Sierra Negra Volcano, Gal&#225;pagos
Numerical modelling of earthquake induced stress changes and dike migration preceding the 2018 eruption of Sierra Negra Volcano, Galápagos Open
Studying the interactions between magmatic and volcano-tectonic processes is critical to understanding the behavior of volcanic systems and the triggering of eruptions. Sierra Negra Volcano, Galápagos is one of the largest basaltic ca…
View article: Acknowledgment of Reviewers
Acknowledgment of Reviewers Open
The Editors of Demography rely on the exper tise and judg ment of out side review ers in selecting man u scripts for pub li ca tion.We thank our many col leagues for their thought ful and pro fes sional con tri bu tions to this pro cess.Th…
View article: Loading of a porous rock with constant micro-seismic event rate suppresses seismicity and promotes subcritical failure
Loading of a porous rock with constant micro-seismic event rate suppresses seismicity and promotes subcritical failure Open
Catastrophic failure is the end result of a progression of damage towards brittle failure on a variety of system scales in the Earth. However, the factors controlling this evolution, and the relationship between deformation and the resulti…
View article: Micromechanics of damage localisation and shear failure of a porous rock: sound and vision
Micromechanics of damage localisation and shear failure of a porous rock: sound and vision Open
Catastrophic failure in brittle, porous materials initiates when structural damage, in the form of smaller-scale fractures, localises along an emergent failure plane or 'fault' in a transition from stable crack growth to dynamic rupture. D…
View article: Data Interpretation Framework for Pile Thermal Integrity Testing
Data Interpretation Framework for Pile Thermal Integrity Testing Open
Given the inherent nature of how deep cast in-situ concrete foundations (piles and diaphragm walls) are constructed, evaluating their integrity is difficult. Several well-established methods for testing integrity have been established, but…
View article: Sangay volcano (Ecuador): the opening of two new vents, a drumbeat seismic sequence and a new lava flow in late 2021
Sangay volcano (Ecuador): the opening of two new vents, a drumbeat seismic sequence and a new lava flow in late 2021 Open
On 2 December, 2021 we recorded a sequence of drumbeat seismic events at Sangay volcano. This sequence lasted several hours and resulted in two explosive emissions whose eruptive columns reached 9 km above crater. Unexpectedly, these explo…
View article: Ground motion and unrest triggering on volcanoes
Ground motion and unrest triggering on volcanoes Open
<p>Dynamic stress perturbations have triggered earthquakes thousands of kilometres away from the source. This process, known as dynamic triggering, occurs due to dynamic excitation from both local and regional earthquakes which trigg…
View article: Seismic velocity changes prior to the 2018 eruption of Sierra Negra volcano, Galapagos Island, using coda wave interferometry.
Seismic velocity changes prior to the 2018 eruption of Sierra Negra volcano, Galapagos Island, using coda wave interferometry. Open
<p>Changes in external stress state and fluid content alter the mechanical properties of an elastic medium. Hence, variations in seismic wave velocity and (crack-induced) seismic anisotropy can be used as proxies for changes in stres…
View article: Micromechanics of damage localisation and shear failure in a porous rock: sound and vision
Micromechanics of damage localisation and shear failure in a porous rock: sound and vision Open
<p>Catastrophic failure in brittle, porous materials initiates when structural damage, in the form of smaller-scale fractures, localises along an emergent failure plane or 'fault' in a transition from stable crack growth to dynamic r…
View article: Forecasting eruptions from long-quiescent volcanoes
Forecasting eruptions from long-quiescent volcanoes Open
Forecasts of eruption are uncertain. The uncertainty is amplified when volcanoes reawaken after several generations in repose, because direct evidence of previous behaviour is rarely available. It fosters scepticism about warnings of volca…
View article: Seismic events miss important grain-scale mechanisms governed by kinematics during shear failure of porous rock
Seismic events miss important grain-scale mechanisms governed by kinematics during shear failure of porous rock Open
Catastrophic failure in brittle, porous materials initiates when smaller-scale fractures localize along an emergent failure plane or 'fault' in a transition from stable crack growth to dynamic rupture. Due to the extremely rapid nature of …
View article: A compact static birefringent interferometer for the measurement of upper atmospheric winds: concept, design and lab performance
A compact static birefringent interferometer for the measurement of upper atmospheric winds: concept, design and lab performance Open
A new compact static wind imaging interferometer, called the Birefringent Doppler Wind Imaging Interferometer (BIDWIN), has been developed for the purpose of observing upper atmospheric winds using suitably isolated airglow emissions. The …
View article: Dynamic earthquake triggering response tracks evolving unrest at Sierra Negra volcano, Galápagos Islands
Dynamic earthquake triggering response tracks evolving unrest at Sierra Negra volcano, Galápagos Islands Open
Dynamically triggered earthquakes track pre-eruptive unrest evolution at Sierra Negra volcano, Galápagos Islands.