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A New 3-D P-wave Velocity Model for Central America using the TeletomoDD Method

Geophysical Journal International - Thu, 11/20/2025 - 00:00
SummaryCentral America’s tectonic complexity arises from the interaction of multiple plates and diverse plate boundaries, resulting in high seismic activity and intricate subduction processes. Three-dimensional seismic velocity models can provide critical constraints on subduction processes and associated earthquake hazard models. Although regional tomographic studies have offered insights into seismic activity and lithospheric processes in Central America, there have been few studies that image the entire region in a consistent manner, likely due to the geological complexity and numerical challenges. In this study, we develop a new high-resolution three-dimensional (3-D) compressional (P)-wave velocity model to investigate the subduction dynamics of the region. We apply the teletomoDD method, which uses both local and global body-wave arrivals to resolve velocity structures. We use the International Seismological Center’s EHB catalog to extract data from 6,026 regional earthquakes from 1965 to 2019, recorded by seismic stations both inside and outside of our study area. Our model is further constrained by incorporating about 30,000 global events recorded by the seismic stations within our study area. We perform both checkerboard and restoration tests to assess the resolution of the model and find that the main features are resolved robustly regardless of the initial models. The model shows a coherent high-velocity anomalies along the Middle America Trench at 50 km depth, suggesting cold, dense subducting slabs. It also captures notable variations in slab geometry, including a slab window in the southern Cocos region starting at ∼75 km depth. Low-velocity anomalies beneath major volcanic systems such as the Central American Volcanic Arc and the Trans-Mexican Volcanic Belt point to slab dehydration, fluid migration, and partial melting processes, whereas the discontinuous distribution of volcanism in Mexico and Central America appears to be influenced by the subduction of the Cocos Plate. Additionally, we identify high-velocity anomalies near the Siqueiros and Clipperton Transform Faults on the East Pacific Rise, possibly caused by mafic magmatic cumulates. The high-velocity anomaly near Swan Islands Transform Fault may reflect locally increased density inferred from previous gravity studies. Our new velocity model offers a consistent seismic structural foundation for further investigations into seismogenic processes, slab geodynamics, petrology, and rheology in Central America.

Synthetic evaluation of two semi-airborne transient electromagnetic (TEM) systems utilizing inductive and galvanic sources in hydrogeological settings

Geophysical Journal International - Thu, 11/20/2025 - 00:00
SummaryRecently, semi-airborne transient electromagnetic (TEM) systems have gained attention in geophysical investigations due to their ability for fast mapping and minimal ground access requirement. These systems consist of a ground-based transmitter source and an inductive receiver coil, carried by an uncrewed aerial vehicle. This study investigates how transmitter source selection in field-based semi-airborne TEM systems affects model parameter uncertainty, using synthetic subsurface models. The simulated dB/dt responses highlight distinct signal characteristics between the galvanic-based system (herein galvanic source) and the inductive-based system (herein inductive source), with differences observed across varying subsurface conditions. An analysis of four synthetic 3-layer models highlights that the inductive-based system resolves shallow conductors better at short offsets, whereas the galvanic-based system is better at resolving parameters for deeper targets at large offsets. Both systems, however, face challenges in accurately resolving resistive targets embedded between conductors, highlighting the need for strategic selection of the transmitter source. The galvanic-based system consistently achieves a higher signal-to-noise ratio (SNR), particularly at large offsets, making it better suited for deep exploration. In contrast, the inductive-based system exhibits lower SNR, higher noise susceptibility, and sign-changing dB/dt responses at increasing offsets adding complexity to data processing and interpretation. Despite these limitations, inductive-based systems enable earlier time measurements with signal magnitudes at short offsets comparable to galvanic-based, due to shorter current turn-off times. In this analysis we have used two system setups utilizing inductive and galvanic sources that reflect commonly used systems, but obviously, assumptions regarding transmitter characteristics such as type, size, waveform, and current amplitude, will influence the results when examining details more closely.

Soil carbon decomposition varies vastly, holding implications for climate models

Phys.org: Earth science - Wed, 11/19/2025 - 21:38
Soil stores more carbon than Earth's atmosphere and plants combined, which makes the speed of soil carbon's decomposition an important variable in models used to predict changes to our climate.

Ancient bog growth reveals shifting Southern Hemisphere winds 15,000 years ago

Phys.org: Earth science - Wed, 11/19/2025 - 20:47
Scientists have revealed that ancient bogs in the Southern Hemisphere hold clues to a major shift in Earth's climate thousands of years ago.

Complex Plumbing Dynamics for Kīlauea Volcano  

EOS - Wed, 11/19/2025 - 19:23
Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: AGU Advances

The Hawaiian Islands formed through the Pacific plate’s movement over a relatively stationary, hot mantle plume, creating a succession of progressively older volcanic centers. New land continues forming on the Big Island’s south side, where the Kīlauea volcano system has remained active for decades. After nearly 40 years of spectacular surface flows entering the sea at Pu’u’ō’ō, volcanic activity shifted to the summit caldera.

Wu et al. [2025] employ seismological techniques to analyze subtle changes in shallow crustal velocities from 2013 to 2018, combining these data with geodetic and geological observations to better understand magma reservoir interactions between Kīlauea’s caldera and Pu’u’ō’ō. Their analysis reveals a fascinating sequence of cross-communication involving pressurization and magma transport processes affected by earthquake valving. When integrated with other monitoring and modeling, such research provides valuable insights into Kīlauea’s plumbing and basaltic volcanic systems more broadly. The work also reemphasizes the importance of seismological monitoring, and deployment of dense seismic networks at as many active volcanoes as possible would enable new comparative analyses.

Citation: Wu, S.-M., Lin, G., & Shearer, P. (2025). Seismic velocity monitoring reveals complex magma transport dynamics at Kīlauea Volcano prior to the 2018 eruption. AGU Advances, 6, e2025AV001759. https://doi.org/10.1029/2025AV001759

—Thorsten Becker, Editor, AGU Advances

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editorial Board

Publication date: November 2025

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 276

Author(s):

Assessment and enhancement of Landsat 8 land surface temperature retrieval using mono window algorithm and machine learning approaches

Publication date: November 2025

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 276

Author(s): Noorfarhah Jasmin Jamaludin, Ahmad Fikri Abdullah, Nur Atirah Muhadi, Aimrun Wayayok

Developing machine learning models for predicting daily relative humidity and solar radiation using lagged time series data inputs in a semi-arid climate

Publication date: November 2025

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 276

Author(s): Jitendra Rajput, Nand Lal Kushwaha, Aman Srivastava, Dinesh Kumar Vishwakarma, A.K. Mishra, P.K. Sahoo, Truptimayee Suna, Lalita Rana, Malkhan Singh Jatav, Jitendra Kumar, Dimple, Shaloo, Himani Bisht, Ashish Rai, Bilel Zerouali, Chaitanya B. Pande, A. Elbeltagi

Solar radiation on complex underlying surfaces in Xinjiang: A typical arid and semi-arid region in the northwestern China

Publication date: November 2025

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 276

Author(s): Chengming Zhang, Xin Liu, Shuyi Chen, Jianrong Bi, Yonghang Chen, Qing He, Ting He, Yunhong Xu, Hui Li

Climatological trends and variability of fog characteristics and meteorological parameters over cities along the Indo-Gangetic Plain

Publication date: November 2025

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 276

Author(s): Deevi Prathima, A.N.V. Satyanarayana

Numerical simulation study on high temporal resolution variation characteristics of atmospheric limb infrared radiation under aurora disturbance

Publication date: November 2025

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 276

Author(s): Fan Wu, Congming Dai, Cong Zhang, Wentao Lian, Shunping Chen, Heli Wei

Virtual Water Gauge from the Synthetic Aperture Radar (SAR) Altimeters for Small Reservoirs in Tropical Regions

Publication date: Available online 17 November 2025

Source: Advances in Space Research

Author(s): Mohd Adha Abdul Majid, Nurul Hazrina Idris, Mohd Nadzri Md Reba, Stefano Vignudelli

Geoscience in the Era of Generative Artificial Intelligence (Geo[AI]-LSM): Understanding the Potential Benefits of Google Gemini in Producing Landslide Susceptibility Mapping

Publication date: Available online 15 November 2025

Source: Advances in Space Research

Author(s): Emrehan Kutlug Sahin, Selçuk Demir, Mert Ozturk, Mehmet Serhan Duzce

Global features of the multi-step ionospheric storm of September 11–21, 2024

Publication date: Available online 15 November 2025

Source: Advances in Space Research

Author(s): L.F. Chernogor, V.O. Bessarabova

Editorial Board

Earth and Planetary Science Letters - Wed, 11/19/2025 - 19:11

Publication date: 15 December 2025

Source: Earth and Planetary Science Letters, Volume 672

Author(s):

Design of BDS-3 signal distortion bias model and analysis of its performance

Publication date: Available online 13 November 2025

Source: Advances in Space Research

Author(s): Saisai Gao, Ran Li, Jiatong Wu, Xiaoyun Wan, Rui Guo, Xiaojie Li, Shanshi Zhou, Guang Yang

Fading of a sulfate-methane transition in deep and hot subseafloor sediments from the Nankai Trough

Earth and Planetary Science Letters - Wed, 11/19/2025 - 19:11

Publication date: 15 December 2025

Source: Earth and Planetary Science Letters, Volume 672

Author(s): Male Köster, Bo Liu, Akira Ijiri, Arthur J. Spivack, Yuki Morono, Fumio Inagaki, Verena B. Heuer, Sabine Kasten, Susann Henkel

Testing the directional recording ability of natural chemical remanent magnetisations using historical sediments

Earth and Planetary Science Letters - Wed, 11/19/2025 - 19:11

Publication date: 15 December 2025

Source: Earth and Planetary Science Letters, Volume 672

Author(s): Evelyn B. Baker, Adrian R. Muxworthy, David Heslop

In situ deformation of antigorite-olivine two-phase mixtures: Implications for dynamics and seismic anisotropy in the mantle wedge

Earth and Planetary Science Letters - Wed, 11/19/2025 - 19:11

Publication date: 15 December 2025

Source: Earth and Planetary Science Letters, Volume 672

Author(s): Rose Hurlow, Wenhao Su, Wen-Yi Zhou, Feng Lin, Lowell Miyagi, Timothy Officer, Tony Yu, Yanbin Wang, Meiqian Wu, Qin Wang, Jin S. Zhang

Impactful dates: Coordinated <sup>40</sup>Ar/<sup>39</sup>Ar geochronology and shock study of the Kamestastin lake impact structure, Canada

Earth and Planetary Science Letters - Wed, 11/19/2025 - 19:11

Publication date: 15 December 2025

Source: Earth and Planetary Science Letters, Volume 672

Author(s): Jennifer Reyné Davis, Carolyn A. Crow, Gordon R. Osinski, Jeffrey Benowitz, Jessica C. Hankins

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