A5040719561- earthquake and tectonic studies
- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- Geological and Geophysical Studies
- Seismic Waves and Analysis
- Earthquake Detection and Analysis
- Linguistics, Language Diversity, and Identity
- Geophysics and Sensor Technology
- X-ray Diffraction in Crystallography
- Coastal and Marine Management
- Geological Studies and Exploration
- Seismic Imaging and Inversion Techniques
- Crystallization and Solubility Studies
- Geological and Tectonic Studies in Latin America
- Geophysics and Gravity Measurements
- Marine and fisheries research
- Methane Hydrates and Related Phenomena
- Satellite Communication Systems
- Geological Formations and Processes Exploration
- Arctic and Russian Policy Studies
- Oceanographic and Atmospheric Processes
- Global Education and Multiculturalism
- Geophysical and Geoelectrical Methods
- GNSS positioning and interference
- Linguistic Variation and Morphology
Durham University
2021-2024
University of Cambridge
2015-2022
GFZ Helmholtz Centre for Geosciences
2018-2020
Grinnell College
2020
Swiss Tropical and Public Health Institute
1993
Historic England
1981
Abstract The lowermost mantle right above the core-mantle boundary is highly heterogeneous containing multiple poorly understood seismic features. smallest but most extreme heterogeneities yet observed are ‘Ultra-Low Velocity Zones’ (ULVZ). We exploit shear waves that diffract along to provide new insight into these enigmatic structures. measure a rare core-diffracted signal refracted by ULVZ at base of Hawaiian plume unprecedentedly high frequencies. This shows remarkably longer time delays...
The presence of a mantle plume beneath Iceland has long been hypothesised to explain its high volumes crustal volcanism. Practical constraints in seismic tomography mean that thin, slow velocity anomalies representative signature are difficult image. However it is possible infer the temperature at depth from effect they have on phase transitions surrounding material. Phase changes olivine component rocks thought be responsible for global discontinuities 410 and 660 km depth, though exact...
Until recently, most of the lower mantle was generally considered to be well-mixed with strong heterogeneity restricted lowermost several hundred kilometres above core–mantle boundary, known as D″ layer. However recent studies have started hint at a potential change in Earth's structure mid-mantle depths beneath transition zone. Here we present continental-wide search Europe and North Atlantic for P-to-s wave converted phases. Our data set consists close 50,000 high quality receiver...
Abstract The Eastern Mediterranean captures the east‐west transition from active subduction of Earth's oldest oceanic lithosphere to continental collision, making it an ideal location study terminal‐stage subduction. Asthenospheric‐ or subduction‐related processes are main candidates for region's ∼ 2 km uplift and Miocene volcanism; however, their relative importance is debated. To address these issues, we present new P S wave arrival‐time tomographic models that reveal fast anomalies...
We use core reflected ScS waves sensitive to a broad region of the core-mantle boundary beneath Hawaii create first high-resolution map Hawaiian ultralow-velocity zone (ULVZ). Positive ScS-S differential times are used identify regions strong slow velocity anomalies in lowermost mantle, and presence pre/post-cursors around main phase confirms sharp top basal ULVZ layer. Pre/post-cursor arrivals mapped into volume across their sensitivity produce detailed image morphology. The variability...
Abstract Volcanic and seismic unrest on the Reykjanes Peninsula in SW Iceland that started late 2019 after ∼800 years of quiescence has drawn wide interest to this on‐land extension Mid‐Atlantic spreading ridge. Here, we use data collected across larger region, covering six volcanic systems associated high‐temperature geothermal areas produce a crustal‐scale shear‐wave velocity model. The model is constructed from receiver functions (RF), pre‐existing surface wave dispersion measurements...
The distribution of chemical heterogeneity beneath hotspots provides important constraints on the source magmatism and mantle convection. Chemical heterogeneities in upper produce discontinuities that can be interrogated seismically. One such discontinuity, X-discontinuity (230-350 km depth), is observed intermittently across globe, with multiple possible causal mechanisms. However, to better understand cause its relationship upwellings, we require global short wavelength observations,...
Abstract Iceland sits astride a mid‐ocean ridge underlain by mantle hot spot. The interplay of these two geological processes has the potential to generate complex and laterally variable crustal structure. thickness Icelandic crust is long running controversial debate, with estimates ranging from thin 20‐km thick 40‐km crust. We present new images first‐order seismic discontinuity structure based on joint inversion receiver function ambient noise‐derived surface wave dispersion data....
Abstract Turbidity currents carve the deepest canyons on Earth, deposit its largest sediment accumulations, and break seabed telecommunication cables. Powerful canyon‐flushing turbidity sensors placed in their path, making them notoriously challenging to measure, thus poorly understood. This study provides first remote measurements of flows, using ocean‐bottom seismographs located outside flow's destructive revolutionizing flow monitoring. We recorded internal dynamics longest flows yet...
Abstract The Marmara region in Turkey is an important geological setting, both from a tectonic and seismic hazard/risk perspective. We present new map of crustal thickness variation across this complex to better understand the interplay past processes that have formed present‐day structure. Maps are created using Ps converted phases receiver function (RF) analysis earthquakes recorded at all publicly available stations national monitoring network (run by AFAD Disaster Emergency Management...
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No fewer than four major tectonic plates (Arabia, Eurasia, India, and Africa) one smaller block (Anatolia) are responsible for seismicity tectonics in the Middle East surrounding region. Geologic development of region is a consequence number first-order plate processes that include subduction, large-scale transform faulting, compressional mountain building, crustal extension. In east, dominated by collision India with driving uplift Himalaya, Karakorum, Pamir Hindu Kush ranges. Beneath...
Seismicity in the Himalaya region predominantly results from collision of India and Eurasia continental plates, which are converging at a relative rate 40–50 mm/yr. Northward underthrusting beneath generates numerous earthquakes consequently makes this area one most seismically hazardous regions on Earth. The surface expression plate boundary is marked by foothills north-south trending Sulaiman Range west, Indo-Burmese Arc east, east-west Front north India. Along western margin plate,...
Non-invasive imaging methods are a useful tool in informing conservation actions for historical buildings. Electrical Resistivity Tomography (ERT) is widely used geophysics to image the subsurface but has been seldom non-invasive of small-scale masonry structures. Here, we propose an adaptation method allowing non-damaging investigation larger-scale stone We report results ERT survey Prebends Bridge Durham, heritage structure constructed 1778. Our assessment based on data acquired paved top...
<div> <p>Borneo is located at the centre of Southeast Asia, which one most active tectonic regions on Earth due to subduction Indo-Australian plate in south and Philippines Sea east. Borneo resides leading edge Sundaland block Eurasian exhibits lower rates seismicity when compared surrounding its intraplate setting. Sulawesi, an island lies just southeast Borneo, characterised by intense multiple zones vicinity. The relationship between two islands poorly...
Abstract The lowermost mantle right above the core-mantle boundary shows a complex and heterogeneous landscape containing multiple poorly understood seismic features visible across wide range of length scales. smallest, but most extreme, heterogeneities yet observed are 'Ultra-Low Velocity Zones' (ULVZ), several which have recently been linked to base plumes. We exploit shear waves that diffract along provide new insight into these enigmatic structures. demonstrate strong frequency-dependent...
<div> <p>The Marmara region in Turkey is an important geological setting, both from a tectonic and seismic hazard/risk perspective. Here we present recently published map of crustal thickness variation across this complex (Jenkins et al., 2020), to aid furthering our understanding the past processes that formed present‐day structure. The was created using Ps converted phases receiver function (RF) analysis earthquakes recorded at all publicly...