Article
Geosciences, Multidisciplinary
Mason Perry, Cyril Muller, Marino Protti, Lujia Feng, Emma M. Hill
Summary: Using continuous geodetic time series, five shallow slow slip events (SSEs) were identified offshore and beneath the Osa peninsula in southern Costa Rica. These events occur approximately every 4-5 years and may potentially limit the magnitude and spatial distribution of future large ruptures.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Satoru Baba, Kazushige Obara, Shunsuke Takemura, Akiko Takeo, Geoffrey A. Abers
Summary: The study revealed the presence of very low frequency earthquakes (VLFEs) around the Nicoya Peninsula, mainly near the trench axis and overlapping with large slip areas of slow slip events. Additionally, low frequency tremor signals were found to occur within the same time windows as VLFEs on high-frequency seismogram envelopes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geology
James R. Bourke, Vadim Levin, Ivonne G. Arroyo, Lepolt Linkimer
Summary: The Panama microplate, located between the Cocos, Nazca, Caribbean, and South American plates, has undergone rapid tectonic changes in the past 10 million years. The region has seen significant seismicity, with a major earthquake occurring along the Caribbean coast of Costa Rica in 1991. Through receiver function analysis, this study provides insights into the crust and upper mantle structure of the region, identifying the position of the Panama microplate boundary and confirming that the Caribbean plate is subducting beneath it. This subduction explains the observed seismic activity and the cessation of volcanic activity in southern Costa Rica.
Article
Oceanography
Viola Alms, Giovanni Romagnoni, Matthias Wolff
Summary: The Gulf of Nicoya, located in the Pacific coast of Costa Rica, has experienced ecosystem degradation due to overfishing and climate variations. This study tested different management scenarios and found that a ban on shrimp trawling is crucial for the recovery of certain target species, but not sufficient for rebuilding the biomass of all key species. Two alternative management scenarios are proposed, focusing on minimizing economic losses or maximizing ecosystem health and biodiversity, both of which require additional reductions in fishing efforts.
OCEAN & COASTAL MANAGEMENT
(2022)
Article
Geochemistry & Geophysics
Ariane Ducellier, Kenneth C. Creager
Summary: Low-frequency earthquakes (LFEs) are small magnitude earthquakes associated with tectonic tremor and slow-slip events. The occurrence of LFEs can be independent of tremor activity and their recurrence intervals vary with the location of seismic events.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Juliette P. Saux, Elias G. Molitors Bergman, Eileen L. Evans, John P. Loveless
Summary: Slow slip events (SSEs) occurring at depths of 30-50 km on the Cascadia Subduction Zone interface indicate the release of accumulated strain. However, previous studies have primarily focused on coupling within the upper 30 km of the interface, which is considered the seismogenic zone. By analyzing reversals in GPS motion and utilizing SSE displacements, this study estimates cumulative slow slip from 2007 to 2021 and examines its impact on interseismic strain accumulation. The findings suggest that moderate to high coupling extends to 40 km depth, and a deeper region beneath the Olympic Peninsula may experience partial aseismic relief through SSEs.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
J. Edwards, Jared Kluenser, Eli Silver, Rachel Lauer, Nathan Bangs, Brian Boston
Summary: The Costa Rican convergent margin is usually seen as an erosive margin, with estimated average losses of sediment. However, new data suggests that the material transfer at the plate boundary is more complex, with a balance between accretion, underplating, basal erosion, and sediment subduction. These budget results differ significantly from previous estimates based on simpler proxies.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
Morgan McLellan, Pascal Audet, Juan Carlos Rosas, Claire Currie
Summary: Slow slip events in subduction zones exhibit variations in behavior, including periodicity and magnitude, both within and across different zones. This study calculates thermal models for the Cascadia subduction zone and finds that temperature and slab geometry variations impact fluid flux rates near the mantle wedge corner where slow slip events occur. The study supports the idea that fluctuations in fluid production rate near the mantle wedge corner may control pore fluid pressure buildup and release during slow slip.
Article
Environmental Sciences
Jeffrey A. Sibaja-Cordero, Eddy H. Gomez-Ramirez
Summary: This study quantified marine litter and its association with human activities in the Gulf of Nicoya, Costa Rica. It found that tourism intensity, river plume influence, and beach cleaning programs were key factors influencing the distribution of marine litter. Effective river basin management, waste disposal programs, and environmental education are crucial in reducing marine litter in tropical countries focused on ecological tourism.
MARINE POLLUTION BULLETIN
(2022)
Article
Geochemistry & Geophysics
Masanao Shinohara, Tomoaki Yamada, Hajime Shiobara, Yusuke Yamashita
Summary: In order to study slow earthquakes, a long-term compact broadband ocean-bottom seismometer was developed by upgrading short-period ocean-bottom seismometers, allowing for a cost-effective increase in the number of broadband seafloor sensors.
SEISMOLOGICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Zaccaria El Yousfi, Mathilde Radiguet, Baptiste Rousset, Allen Husker, Ekaterina Kazachkina, Vladimir Kostoglodov
Summary: In the Mexican subduction zone, slow slip events with various durations have been observed, accompanied by microseismicity. By analyzing a 10-year tremor catalog, this study identified clusters of short-lasting slip events occurring during tremor times, which contribute to large slow slip events. In addition, low amplitude transients lasting 8 - 9 days were also found to occur at tremor times and locations.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Aristides Alfaro, Esteban Gazel, William M. White, Brian Jicha, Troy Rasbury
Summary: The study reveals that the highly enriched igneous rocks in the Talamanca Cordillera are related to subduction processes rather than lower crustal melting. It is suggested that these rocks require an input of an incompatible element-enriched component, similar to the Cocos Island Province in the Pacific Ocean. The presence of this component is interpreted to be the result of slab melting of subducted seamounts, indicating a critical step for the generation of continental crust-like rock compositions in southern Central America.
Article
Geosciences, Multidisciplinary
Shannon L. Fasola, Noel M. Jackson, Charles A. Williams
Summary: The study on the Manawatu region in New Zealand reveals a relationship between tremor and slow slip events (SSEs) and suggests that long-term SSEs may influence small SSEs. This research is significant in understanding the mechanism of earthquakes and crustal movements.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Review
Multidisciplinary Sciences
Whitney M. Behr, Roland Buergmann
Summary: This article reviews the constraints on SST deformation processes, including geophysical observations and geological observations. Research shows that the SST source region is an environment rich in fluids and high fluid pressure. In regions of mixed lithology and near-lithostatic fluid pressures, a combination of frictional-viscous shear may scale with the tremor component of SST.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
J. Munoz-Montecinos, W. M. Behr
Summary: This article examines the permeability and porosity of a subduction interface in Syros Island, Greece, using high-resolution digital outcrop data and microstructural analysis. The study finds high permeability through vein-filled fractures in a lower permeability matrix, with estimated transient permeabilities ranging from 10-14 to 10-15 m2 and fracture porosities of 1%-10%. These findings are important for understanding fluid-seismicity interactions in subduction zones.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Joshua D. Carmichael, Andrew D. Thiel, Phillip S. Blom, Jacob Walter, Fransiska K. Dannemann Dugick, Stephen J. Arrowsmith, Chris G. Carr
Summary: This study reports on the source of seismoacoustic pulses observed in Oklahoma in the summer of 2019, which were caused by routine ammunition disposal operations. The research also shows that dense seismic networks can record multiscale atmospheric processes in the absence of infrasound arrays.
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
(2022)
Article
Geochemistry & Geophysics
Jack N. Williams, Luke N. J. Wedmore, Christopher A. Scholz, Folarin Kolawole, Lachlan J. M. Wright, Donna J. Shillington, Ake Fagereng, Juliet Biggs, Hassan Mdala, Zuze Dulanya, Felix Mphepo, Patrick R. N. Chindandali, Maximilian J. Werner
Summary: The Malawi Active Fault Database (MAFD) is an open-access geospatial database containing 113 fault traces in Malawi and neighboring Tanzania and Mozambique. It is used to understand the regional seismic hazard and tectonic evolution. The MAFD incorporates a multidisciplinary dataset including digital elevation models, geological mapping, seismic reflection surveys, and magnetic and gravity data. The study finds that the distribution of fault lengths in Malawi follows a power law.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geosciences, Multidisciplinary
Jack N. Williams, Ake Fagereng, Luke N. J. Wedmore, Juliet Biggs, Hassan Mdala, Felix Mphepo, Michael Hodge
Summary: This study investigates the earthquake energy dissipation along low displacement faults and the impact of pre-existing weaknesses. The research findings suggest that low displacement faults consume more energy through fracturing and fault formation compared to mature faults. However, minimal evidence was found for earthquake energy dissipation in the surrounding wall rock of the Bilila-Mtakataka Fault in Malawi, despite geomorphic evidence for M-W 7.5-8 earthquakes.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
R. M. Churchill, M. J. Werner, J. Biggs, A. Fagereng
Summary: Aseismic afterslip can significantly redistribute crustal stresses and drive aftershock sequences. This study analyzed 148 afterslip studies following large earthquakes and found that afterslip and coseismic moments scale near-linearly. The study also identified the scaling relationships between afterslip area and average slip with coseismic moment. The ratio of afterslip to coseismic moment varied widely and was influenced by various factors.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Archaeology
R. Pasteka, P. Zahorec, J. Papc, J. Mrlina, H. -j. Gotze, S. Schmidt
Summary: This study investigates the use of highly accurate microgravimetric measurements to map the recently discovered muon chamber in the Great Pyramid of Giza. By using modern gravimeters and realistic model calculations, researchers aim to understand the composition and structure of the pyramid chamber.
JOURNAL OF ARCHAEOLOGICAL SCIENCE-REPORTS
(2022)
Article
Geochemistry & Geophysics
Stanley Tze Hou Yip, Juliet Biggs, Marie Edmonds, Philippa Liggins, Oliver Shorttle
Summary: Ground deformation and volcanic outgassing during volcanic eruptions are fundamentally linked through magma degassing and compressibility. We used thermodynamic models to predict co-eruptive SO2 flux and surface deformation based on petrological data. Sensitivity tests showed that magma water content has the most impact on both SO2 flux and volume change. Our findings have implications for basaltic systems in arc and ocean island settings, with arc magmas being more compressible and exhibiting less deformation during eruptions.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
Paul Ogwari, Jacob I. Walter, Xiaowei Chen, Andrew Thiel, Fernando Ferrer, Isaac Woelfel
Summary: During routine operations monitoring Oklahoma earthquakes, it was found that certain earthquakes had closely overlapping phases in both space and time. Further analysis revealed that these earthquakes were not distinct events, but rather had multiphase arrivals and longer coda duration due to unique ray paths encountering impedance contrasts. A classification scheme was developed to separate single earthquakes, overlapping earthquakes, and earthquakes associated with multiphase arrivals. Seismic wave propagation modeling and waveform correlation were used to distinguish phases from overlapping earthquakes and crustal reverberations.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Ajay Kumar, Mauro Cacace, Magdalena Scheck-Wenderoth, Hans-Juergen Goetze, Boris J. P. Kaus
Summary: The dynamics of the Alps and surrounding regions remain not fully understood due to the non-unique interpretation of its upper-mantle architecture. By clustering available shear-wave tomography models, three end-member scenarios of lithospheric thickness and slab geometries were derived and used as input for geodynamic simulations, revealing a potential explanation for observed seismicity.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
R. M. Churchill, M. J. Werner, J. Biggs, A. Fagereng
Summary: This study examines the correlation between relative afterslip moment and aftershock sequence characteristics and finds no correlation. The findings provide empirical constraints on the link between afterslip and potentially damaging Mw >= 4.5 aftershocks, and raise questions regarding the role of afterslip in aftershock generation.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Fabien Albino, Juliet Biggs, Milan Lazecky, Yasser Maghsoudi
Summary: Since the launch of Sentinel-1 mission, automated processing systems have been developed for near real-time monitoring of ground deformation signals. In this study, a regional analysis was performed on 64 volcanic centres along the East African Rift System (EARS) over a period of 5 years. The study found that atmospheric signal correction is less important for the arid and low-elevation EARS volcanoes compared to other volcanic environments. The research also identified 16 volcanoes with cumulative displacements exceeding three times the temporal noise of the time series, including previously reported deformation signals and two new ones.
Article
Geochemistry & Geophysics
William Hutchison, Euan R. D. Ogilvie, Yafet G. Birhane, Peter H. Barry, Tobias P. Fischer, Chris J. Ballentine, Darren J. Hillegonds, Juliet Biggs, Fabien Albino, Chelsea Cervantes, Snorri Guobrandsson
Summary: East Africa has significant untapped geothermal reserves, with exploration mainly focused on young volcanic areas. However, there are potential geothermal sites without a clear link to active volcanoes. This study investigates a fault-controlled geothermal system north of Lake Abaya in the Main Ethiopian Rift, using remote sensing and field observations. The findings suggest that fault-controlled geothermal systems offer viable prospects for geothermal exploration, as they do not require volcanic unrest or recent volcanism.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Geochemistry & Geophysics
Fikret Dogru, Fabien Albino, Juliet Biggs
Summary: One of the main obstacles in using satellite radar data to monitor natural hazards is the presence of atmospheric signals, which can mask or mimic ground deformation signals. To overcome this, the study applies high-resolution weather models and an empirical phase-elevation method to correct interferograms. The results show that atmospheric corrections are crucial for monitoring high-relief volcanoes in arid continental climates like Turkey.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
J. N. Williams, M. J. Werner, K. Goda, L. N. J. Wedmore, R. De Risi, J. Biggs, H. Mdala, Z. Dulanya, A. Fagereng, F. Mphepo, P. Chindandali
Summary: Historical and instrumental earthquake catalogs may not accurately reflect the long-term distribution of seismicity in low strain rate regions. Therefore, probabilistic seismic hazard analysis (PSHA) should consider geologic and geodetic data to incorporate fault-based seismogenic sources. The study explores these issues in the context of a new PSHA for Malawi, which has a thick seismogenic layer and a growing exposure to seismic hazard. The results emphasize the importance of careful fault source modeling in PSHA and the need for new fault-based PSHA in the East Africa Rift.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
M. J. W. Bemelmans, J. Biggs, M. Poland, J. Wookey, S. K. Ebmeier, A. K. Diefenbach, D. Syahbana
Summary: During a volcanic crisis, high-resolution satellite SAR imagery was used to detect intra-crater uplift preceding the onset of eruptive activity. The deformation was attributed to the pressurization of a shallow hydrothermal system by magmatic gases and fluids. The observations have important implications for eruption forecasting and demonstrate the potential of monitoring with high-resolution SAR.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geosciences, Multidisciplinary
Juliet Biggs, Nantheera Anantrasirichai, Fabien Albino, Milan Lazecky, Yasser Maghsoudi
Summary: Radar (SAR) satellite imagery can be used for global volcano monitoring and eruption forecasting, but manual inspection limits the exploitation of large datasets. In this study, machine learning is used to automatically process nearly 600,000 images, demonstrating its applicability and limitations for detecting volcano deformation signals.
BULLETIN OF VOLCANOLOGY
(2022)