Article
Geochemistry & Geophysics
Yu Wei, Shuangxi Zhang, Mengkui Li, Tengfei Wu, Yujin Hua, Yu Zhang, Jianfeng cai
Summary: The study revealed the existence of lower crust delamination and high-velocity lithospheric mantle in the 3-D model constructed in the Qinling-Dabie orogenic belt and its adjacent region, providing support for a two-stage exhumation model of HP/UHP rocks in the study area. The model also showed two deep-rooted high-velocity domes formed in the Dabbashan orocline and described the destruction of lithospheric mantle beneath the Yangtze Block.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geosciences, Multidisciplinary
Shindy Rosalia, Sri Widiyantoro, Phil R. Cummins, Tedi Yudistira, Andri Dian Nugraha, Zulfakriza Zulfakriza, Ahmad Setiawan
Summary: This paper presents a depth inversion study of Rayleigh wave group velocities in western Java, Indonesia, to obtain an S-wave velocity model. By utilizing seismic ambient noise cross-correlation, the study reveals a pronounced NE-SW contrast of low and high Vs in the shallow crust, which correlates well with the Bouguer anomaly map. The low Vs region is interpreted as alluvial and volcanic products, while the high Vs region is associated with volcanism from previous episodes of subduction. The study provides valuable insights for future earthquake research in the region.
GEOSCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Tahiry A. Rajaonarison, D. Sarah Stamps, John Naliboff, Andrew Nyblade, Emmanuel A. Njinju
Summary: Geodynamicists use high-resolution 3D thermomechanical models to investigate the forces driving continental rifting in the East African Rift. They find that the anomalous surface deformation and seismic anisotropy in the rift are primarily driven by northward mantle flow associated with the African Superplume.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Shanshan Wu, Youqiang Yu, Ting Yang, Mei Xue, Frederik Tilmann, Haopeng Chen
Summary: This study uses seismic data and ambient noise tomography to construct a 3-D crustal shear-wave velocity (Vs) model beneath the Indochina Peninsula. The results show a low-Vs anomaly in the mid-lower crust of the Shan-Thai Block, which may be related to crustal flow from Southeast Tibet. The Khorat Plateau behaves as a rigid block but shows low-Vs anomalies in the lower crust and below the Moho, indicating partial modification by mantle-derived melts. The strike-slip shearing motions of the Red River Fault may dominate crustal deformation at its western flank, where a low-Vs anomaly is observed in the upper-middle crust.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Multidisciplinary Sciences
Matthew R. Agius, Catherine A. Rychert, Nicholas Harmon, Saikiran Tharimena, J. -Michael Kendall
Summary: Studies have shown that seismic discontinuities in the mantle transition zone appear to thin, consistent with slow shear-wave velocities in the mantle. Beneath the Mid-Atlantic Ridge, seismic velocities in the mantle transition zone are on average slower than those beneath older Atlantic Ocean seafloor. These observations suggest that material transfer from the lower to the upper mantle is linked to the Mid-Atlantic Ridge.
Article
Multidisciplinary Sciences
Leiming Zheng, Xiaoping Fan, Peng Zhang, Jingrun Hao, Hao Qian, Tuo Zheng
Summary: This study utilized group-velocity ambient noise tomography to detect and study the structure of the Mufushan-Jiaoshan fault in Zhenjiang area, China. The results showed different characteristics of shear-wave velocity at different depths along the fault, with the gradient zone potentially indicating the location of the main fracture surface.
SCIENTIFIC REPORTS
(2021)
Article
Geosciences, Multidisciplinary
E. L. Wilson, K. S. Harpp, D. M. Schwartz, R. Van Kirk
Summary: Understanding the evolution of ocean island volcanoes provides insight into mantle plumes, plume-ridge interaction, and volcanic risks. This study of the Galapagos Islands reveals the geochemical evolution of Santa Cruz Island over the past 2 million years. The analysis shows that lavas from the island have become more evolved and isotopically enriched as they moved away from the plume. The findings contribute to our understanding of the behavior of mantle plumes and the potential hazards associated with aging islands.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
Sang-Jun Lee, Seongryong Kim, Junkee Rhie, Tae-Seob Kang, YoungHee Kim
Summary: This study used ambient noise data from a temporary seismic network on Jeju Island to image the upper crustal structures. The results showed the presence of layers with negative and positive anisotropy at different depths, which help explain the evolution of the Jeju Island volcanoes.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Yu Wei, Shuangxi Zhang, Mengkui Li, Tengfei Wu, Yujin Hua, Yu Zhang, Jianfeng Cai
Summary: In this study, a 3-D S-wave velocity model was constructed to reveal the characteristics of the Qinling-Dabie orogenic belt and its collision processes and tectonic evolution with the North China Block and Yangtze Block. The results support a two-stage exhumation model for the high-pressure/ultra-high-pressure rocks and provide evidence for the delamination of the lower crust in the orogenic belt.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Albert Okrah Malory, Xuewei Bao, Zhongen Chen
Summary: In this study, a new model of radially anisotropic shear velocity in the crust and upper mantle beneath Southern Africa is presented using ambient noise tomography. The findings suggest a complex flow pattern in the crust and upper mantle, likely resulting from multiple thermo-tectonic events.
Article
Multidisciplinary Sciences
Simon N. Stephenson, Patrick W. Ball, Fred D. Richards
Summary: Large igneous provinces (LIPs) formed by short-lived magmatic events have significant impacts on global geodynamic, tectonic, and environmental processes. By analyzing geochemical and seismological data, we found a positive correlation between the thickness of lithosphere and time since eruption beneath LIPs. This suggests systematic destruction and subsequent regrowth of lithospheric mantle during and after LIP emplacement.
Article
Geosciences, Multidisciplinary
Ping Tan, Xiaofeng Liang, Wei Li, Chenglong Wu
Summary: This study obtained a high-resolution crustal S-wave velocity model beneath the Tibetan Plateau and adjacent areas using ambient noise tomography. The images reveal the limited scale of crustal flow and the influence of different deep processes on surface deformation in various regions of the Tibetan Plateau.
Article
Geochemistry & Geophysics
Derek L. L. Schutt, Robert W. W. Porritt, Clement Esteve, Pascal Audet, Jeremy M. M. Gosselin, Andrew J. J. Schaeffer, Richard C. C. Aster, Jeffrey T. T. Freymueller, Joel F. F. Cubley
Summary: The Mackenzie Mountains in Canada are currently uplifting despite being far from the nearest plate boundary. Tomographic inversion reveals a low-velocity structure in the lithosphere that extends upward and is associated with the ongoing uplift and seismicity. Strain transfer from the Gulf of Alaska boundary plays a driving role in the uplift, causing the crust to translate and buckle against the craton. Azimuthal anisotropy in the lithosphere indicates misalignment between asthenosphere flow and lithospheric strain.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Nanqiao Du, Zhiwei Li, Tianyao Hao, Xin Xia, Yutao Shi, Ya Xu
Summary: A joint tomographic inversion method combining seismic surface wave dispersion and gravity data was developed in this study to achieve more reliable crustal 3-D shear wave structures. The method was shown to better match the gravity data and provide more constraints into the model resolution, improving the reliability of the results.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Lixue Ma, Tao Xu, Yinshuang Ai, Jinhui Yang, Yingjie Yang, Enbo Fan, Long Li, Jue Hou, Weiyu Dong
Summary: In this study, a high-resolution, 3-D S wave velocity (Vs) model of the crust and uppermost mantle beneath the Liaodong area at the northeast margin of the North China Craton (NCC) is presented. The model is based on ambient noise tomography and reveals different Vs anomalies on different sides of the Tanlu Fault.
Article
Geography
Alexandra E. Huff, Paraskevi Nomikou, Lisa A. Thompson, Emilie E. E. Hooft, Ian J. Walker
Summary: Geologic maps are essential for natural hazard assessments, but creating them for submarine areas is challenging due to limited physical access. Submarine geomorphologic maps offer geologic context and spatial information for risk management, generated from remotely sensed data like digital elevation models. This workflow presents a method for applying planetary geologic mapping to submarine data, aiding hazard assessments of submarine environments.
Article
Geochemistry & Geophysics
B. A. Heath, E. E. E. Hooft, D. R. Toomey, M. Paulatto, C. B. Papazachos, P. Nomikou, J. Morgan
Summary: In volcanic arcs like the Aegean, tectonic processes have a significant control on magmatism, with regional-scale tectonic stresses leading to oriented faulting across the region. Local-scale faults/fractures do not necessarily correlate with magmatic features, indicating that regional processes have a greater impact on magmatism than local features. The alignment of magmatic features shows strong tectonic control, suggesting that magmatic processes are strongly influenced by regional-scale tectonic processes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
F. Schmid, G. Petersen, E. Hooft, M. Paulatto, K. Chrapkiewicz, M. Hensch, T. Dahm
Summary: The seismic activity of the Kolumbo volcano is related to the distribution of magma and pressure disturbances. The study suggests that future eruptions are probable and monitoring of the volcano is highly advisable.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
K. Chrapkiewicz, M. Paulatto, B. A. Heath, E. E. E. Hooft, P. Nomikou, C. B. Papazachos, F. Schmid, D. R. Toomey, M. R. Warner, J. V. Morgan
Summary: Arc volcanoes are characterized by complex systems of molten-rock reservoirs. A high-resolution technology has been used to image a small, high-melt-fraction magma chamber in a submarine volcano near Santorini, Greece. This discovery challenges existing eruption forecasts and models of magma differentiation.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Review
Geosciences, Multidisciplinary
Michele Paulatto, Emilie E. E. Hooft, Kajetan Chrapkiewicz, Benjamin Heath, Douglas R. Toomey, Joanna V. Morgan
Summary: Seismic imaging methods have been crucial in understanding the physical properties and dynamics of magmatic systems. However, there are still challenges in imaging volcanoes due to the complex physics of wave propagation. This review summarizes the advantages and limitations of common imaging methods and proposes best practices for their implementation. The seismological evidence suggests that magma storage is dominated by low-melt fraction crystal mush, but small and medium-sized high-melt fraction magma chambers cannot be ruled out due to the limitations of seismic resolution. The use of multiple tomographic imaging methods and wider adoption of methods that use more of the seismic wavefield promise to overcome these limitations and provide more reliable constraints on melt fractions.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Nikos Chatzis, Costas Papazachos, Nikos Theodoulidis, Panagiotis Hatzidimitriou, Georgios Vougioukalakis, Michele Paulatto, Ben Heath, Emilie Hooft, Douglas Toomey, Marios Anthymidis, Chrisa Ventouzi
Summary: The geometry of the pre-volcanic basement of Santorini has been studied to understand its volcanic history and assess seismic hazard. Both passive and active source data were used to investigate the geometry, and the results show a linear relationship between the thickness of pyroclastic formations and their fundamental resonance period. The findings are consistent with previous studies but with some local differences, and they provide valuable insights for understanding the volcanic and seismic activities in Santorini.
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Johan T. Gilchrist, A. Mark Jellinek, Emilie E. E. Hooft, Sean Wanket
Summary: This study uses scaled analogue experiments and spectral analysis of well-preserved concentric terracing of seafloor deposits to understand the dynamics and hazards of submarine caldera-forming explosive eruptions. It reveals that collapsing submarine eruption columns deliver material in periodic annular sedimentation waves, which can lead to tsunamis, pyroclastic density currents, and the formation of concentric terraces. The findings provide insights into the classification and estimation of eruption rates from terraced deposits.
Article
Multidisciplinary Sciences
Jens Karstens, Jonas Preine, Gareth J. Crutchley, Steffen Kutterolf, Willem G. M. van der Bilt, Emilie E. E. Hooft, Timothy H. Druitt, Florian Schmid, Jan Magne Cederstrom, Christian Huebscher, Paraskevi Nomikou, Steven Carey, Michel Kuehn, Judith Elger, Christian Berndt
Summary: In this study, seismic reflection and P-wave tomography datasets were integrated with computed tomography-derived sedimentological analyses to estimate the volume of the iconic Minoan eruption. The results revealed a total eruption volume of 34.5 +/- 6.8 km(3), with different proportions of tephra fall deposits, ignimbrites, intra-caldera deposits, and lithics. These volume estimates were consistent with an independent caldera collapse reconstruction. The findings demonstrate the importance of complementary geophysical and sedimentological datasets for reliable eruption volume estimates and volcanic hazard assessments.
NATURE COMMUNICATIONS
(2023)
Article
Geochemistry & Geophysics
Josef Dufek, Kathy Cashman, Emilie Hooft, Paul Bedrosian
Summary: Volcanic activity is influenced by crustal pathways and reservoirs, and the Cascades provide a natural laboratory for studying this influence. The interaction between magma and the crust of the overriding North American plate has resulted in diverse storage conditions.
Proceedings Paper
Computer Science, Hardware & Architecture
Juno Mayer, Valerie Sahakian, Emilie Hooft, Douglas Toomey, Ramakrishnan Durairajan
Summary: The study aims to assess the resilience of critical Internet infrastructure in the U.S. Pacific Northwest to seismic shaking, revealing that approximately 65% of fiber links and cell towers are susceptible to strong earthquakes. The metropolitan areas of Seattle-Tacoma-Bellevue and Portland-Vancouver-Hillsboro have a 10% chance of experiencing strong to severe earthquakes, highlighting the need for mitigation strategies.
PASSIVE AND ACTIVE MEASUREMENT, PAM 2021
(2021)
Article
Geochemistry & Geophysics
Melissinos Paraskevas, Demitris Paradissis, Konstantinos Raptakis, Paraskevi Nomikou, Emilie Hooft, Konstantina Bejelou
Summary: This study used gravity measurements and data analysis to explore the internal structure and geological changes of a volcano in Santorini, Greece. The results showed ongoing volcanic activity within the caldera both before and after the unrest period of 2011-2012.
CONTRIBUTIONS TO GEOPHYSICS AND GEODESY
(2021)