🌟OPEN ACCESS🌟 New Constraints on Northeast Seattle Basin Structure from Converted Seismic Waves #TSR The Seattle basin spans the Seattle-Bellevue metropolitan area in Washington State’s Puget Lowland. This deep sedimentary basin can significantly influence earthquake-related shaking and seismic hazards. In a new paper, a team from the U.S. Geological Survey (USGS) determines the structure of a portion of the basin and its underlying basement rock. To do so, the team used data from a deep local crustal earthquake that occurred about 35 kilometers northeast of Seattle that was recorded by a 100-station nodal array deployed in 2019. The team found evidence of a shallow basement structure below northern Lake Washington that they suggest could be associated with the eastern boundary of Siletzia. Siletzia is a tens-of-millions-of-years-old oceanic plateau and island arc that attached itself to North America about 50 million years ago, forming the basement rock under western Oregon and Washington. https://lnkd.in/gkypyuA3

The 6th volume of our U.S. Geological Survey (USGS) report series on #ungulate migrations across the Western United States is LIVE! I am so proud to have contributed to this huge collaborative effort featuring 23 herds of mule deer, elk, and pronghorn. With this latest volume, the series includes details and maps of the migrations and seasonal ranges for a total of 237 unique herds—an incredible feat. And stay tuned, because volume 7 is in the works! Check out the full report and available data below! Report: https://lnkd.in/ekt8BUAb Download data from the report for free: https://lnkd.in/e3GmR58b Or, view the data from all 6 volumes in the report series on: https://lnkd.in/eJwp26Gk

Recent research highlights that seismic activity in California is influenced not only by tectonic forces but also by seasonal changes in groundwater levels. Analysis of data from 2006 to 2022 shows that regions with greater fluctuations in groundwater experience up to a 10% seasonal increase in seismic events, particularly in Northern California. This increase typically lags peak groundwater changes by about two weeks. The findings provide valuable insights for refining earthquake nucleation models and underscore the importance of considering hydrological dynamics and human activities in seismic risk assessments.

Bed Slope Study on Turbidity and Sediment 🌊 New research from Delft University of Technology (Department of Maritime and Transport Technology), National Ilan University, and Deltares reveals how bed slope dramatically changes the way turbidity currents interact with obstacles. In reservoirs and submarine environments, engineers rely on submerged obstacles to trap sediment and protect critical infrastructure. Yet until now, the influence of the underlying bed slope on these obstructed flows remained largely unexplored, despite slopes being a fundamental feature of real-world systems. Using high-resolution Large Eddy Simulations (LES) with a mixture-model approach, we systematically tested six bed slopes (0 % to 4.5 %) while keeping inlet conditions identical and placing a triangular obstacle in the channel. The model was first validated against the laboratory experiments of Abhari et al. (2018) and then used to examine quasi-steady flow behaviour upstream of the obstacle in detail. Key findings (high-level): • Steeper slopes markedly increase flow velocities and sediment transport capacity, not through higher concentrations, but through enhanced inertia. • Obstacle sediment-retention efficiency drops significantly on steeper beds as more material bypasses the structure. • Recirculation zones appear only on mild slopes (0–1.5 %); they vanish on steeper slopes (3–4.5 %) where inertia overcomes the adverse pressure gradient. • Local densimetric Froude number analysis confirms a clear shift in flow regime across the obstacle, with the transition becoming sharper at higher slopes. These insights directly inform the design of reservoir sediment-control structures and improve predictions of natural turbidity-current deposits on irregular seabeds. 👏 Shoutout to the research team: Said Alhaddad, Ching-Sen Wu, and lynyrd de wit. For the complete methodology, detailed velocity/concentration profiles, layer-averaged results, and all figures, read the full open-access paper: “Effect of bed slope on turbidity currents interacting with an obstacle: Insights from Large Eddy Simulations” Marine Geology, 2026 → https://lnkd.in/gUd9xCrz (Code: https://lnkd.in/gBxHwENQ) #TurbidityCurrents #SedimentTransport #HydraulicEngineering #ReservoirManagement #LargeEddySimulation #MarineGeology #Deltares #TUDelft

Time History Analysis for Deep Excavations — Capturing Seismic Behavior Over Time For seismic regions, equivalent static checks don’t always tell the full story. Time history analysis allows us to see how excavation systems respond throughout the entire earthquake event. With DeepEX, we can: ⚡ Calculate time-dependent seismic pressures 📈 Define trigonometric time histories or import NGA earthquake records 🎯 Control maximum seismic acceleration, duration, and number of steps 📊 Review result graphs and FEM shadings at each time step This approach provides deeper insight into wall forces, displacements, and soil response under dynamic loading—especially for complex or critical projects. 👉 When working in seismic zones, do you rely mainly on pseudostatic methods, or do you also use time history analysis? #DeepEX #SeismicDesign #TimeHistoryAnalysis #DeepExcavation #GeotechnicalEngineering #FEMAnalysis"

https://lnkd.in/dzEn3bQ4 Groundwater modelers should be familiar with and have access to systematic methods for translating physical subsurface geology into a numerical representation. Other hydrogeologists will benefit from understanding the process. This book introduces techniques for creating the underlying geologic framework of groundwater flow models. It is arranged around a hypothetical site with contaminated groundwater, beginning with a discussion of data collection and geologic interpretation, then delves into the steps required to build a realistic numerical model. The reader will find that many of the methods and calculations can be applied with tools as simple as paper and pencil. Links to publicly available computing resources are provided where possible. https://lnkd.in/dyg7eFGy

📢 New Publication in #GeoHazards 📘 Machine Learning Analysis of Landslide Susceptibility in the Western Québec Seismic Zone of Canada ✍️ Kevin Potoczny, Katsuichiro Goda, and Abouzar Sadrekarimi This study applies advanced machine learning techniques to assess landslide susceptibility in a seismically active region, offering valuable insights for hazard mitigation and risk-informed land-use planning. 🔗 Read the full article here: https://brnw.ch/21x0QpH #Landslides #MachineLearning #SeismicRisk #DisasterPrevention #RiskAssessment

Leveraging GIS & Remote Sensing for Gold Prospecting in the Maru Schist Belt. I’m excited to share my latest Target Generation Map for gold exploration within the Maru Schist Belt. By integrating multiple geological and secondary environmental datasets, I’ve been able to delineate high-potential zones with greater precision. The analysis was driven by a weighted overlay of the following key layers: . Lithological Control: Detailed Geology of the Schist belt. . Structural Influence: Lineament Density (identifying shear zones and fractures). . Hydrothermal Alteration: Sentinel-2 Band Ratios for Clay and Iron Oxide minerals. . Geomorphology: Drainage Density and Slope analysis to understand dispersion and accessibility. This data-driven approach minimizes exploration risk and focuses field sampling on the "Very High" potential targets identified in red. I’d love to hear your thoughts on these weighting factors. How do you prioritize Geology, lineaments and hydrothermal alterations in your workflow? #Geology #GoldExploration #GIS #RemoteSensing #QGIS #MineralProspecting #MiningNigeria #Geoscience

New paper alert ‼️ 📉 How much do magnitude uncertainties and completeness bias our estimates of seismic parameters ? Earthquake catalogs combine heterogeneous datasets (instrumental and historical) with varying completeness over time - and with magnitude uncertainties that are usually neglected. 🆕 In our recent paper, “Long-Term b Value and Seismic Rate from Earthquake Catalogs with Time-Varying Completeness and Uncertain Magnitudes” (BSSA), we propose a probabilistic framework to jointly estimate : • the b value • the seismic rate (a) while accounting for varying detection and magntidue uncertainties ! 🔍 The key idea is to explicitly incorporate time-varying detection function and magnitude uncertainties into the inference, rather than correcting for them beforehand. ➡️ This leads to more consistent and robust estimates, especially for long-term seismic hazard assessment (PSHA). As an illustration, we apply the method to the Alpin region in France, combining historical and instrumental seismicity. 📑 Read the whole story, credits and acknowledgments here : https://lnkd.in/dfXC4Z59 This work was founded in the framework of the SIGMA3 (https://sigma-programs.com/) project 2024-2028. #seismology #psha #france

𝗛𝗼𝘄 𝘁𝗼 𝗗𝗶𝘀𝘁𝗶𝗻𝗴𝘂𝗶𝘀𝗵 𝗣𝗮𝘁𝗰𝗵 𝗥𝗲𝗲𝗳𝘀 𝗳𝗿𝗼𝗺 𝗖𝗼𝗻𝘁𝗼𝘂𝗿𝗶𝘁𝗲 𝗠𝗼𝘂𝗻𝗱𝘀 𝗶𝗻 𝗦𝗲𝗶𝘀𝗺𝗶𝗰 𝗗𝗮𝘁𝗮: In seismic interpretation, mounded features are commonly observed in subsurface data. However, not all mounds represent the same geological origin. Two features that may appear similar on seismic sections are carbonate patch reefs and contourite mounds. Correctly distinguishing between them is essential because they form in very different depositional environments and have different implications for reservoir potential. 1️⃣ 𝗪𝗵𝗮𝘁 𝗔𝗿𝗲 𝗣𝗮𝘁𝗰𝗵 𝗥𝗲𝗲𝗳𝘀?: Patch reefs are isolated carbonate build-ups formed by biological organisms such as corals, algae, and other carbonate-producing marine life. They typically grow in shallow, warm marine environments with clear water and limited clastic sediment input. Key characteristics include:   • Localized carbonate mounds   • Growth controlled by biological activity   • Often associated with carbonate platforms or shelves   • Potential high-porosity reservoirs 2️⃣ 𝗪𝗵𝗮𝘁 𝗔𝗿𝗲 𝗖𝗼𝗻𝘁𝗼𝘂𝗿𝗶𝘁𝗲 𝗠𝗼𝘂𝗻𝗱𝘀? Contourite mounds are sedimentary deposits formed by bottom currents that flow parallel to the continental slope. These currents transport and deposit fine-grained sediments, forming elongated mounds known as contourite drifts. Key characteristics include:   • Deposits controlled by deep-water currents   • Often found along continental slopes and basin margins   • Composed mainly of fine-grained sediments   • Typically low reservoir potential Unlike reefs, contourite mounds are not biologically constructed and usually lack strong reservoir properties. 3️⃣ 𝗦𝗲𝗶𝘀𝗺𝗶𝗰 𝗖𝗵𝗮𝗿𝗮𝗰𝘁𝗲𝗿𝗶𝘀𝘁𝗶𝗰𝘀 𝗼𝗳 𝗣𝗮𝘁𝗰𝗵 𝗥𝗲𝗲𝗳𝘀 Patch reefs often show distinctive seismic signatures:   • Mounded geometry with steep flanks   • Chaotic or discontinuous internal reflections   • Onlap of surrounding sediments onto the reef flanks   • Strong reflections at reef boundaries These patterns reflect the complex biological framework and growth stages of reef systems. 4️⃣ 𝗦𝗲𝗶𝘀𝗺𝗶𝗰 𝗖𝗵𝗮𝗿𝗮𝗰𝘁𝗲𝗿𝗶𝘀𝘁𝗶𝗰𝘀 𝗼𝗳 𝗖𝗼𝗻𝘁𝗼𝘂𝗿𝗶𝘁𝗲 𝗠𝗼𝘂𝗻𝗱𝘀 Contourite mounds display different seismic features due to their sedimentary origin:   • More elongated or drift-like shapes   • Parallel or gently inclined internal reflections   • Continuous stratified layering   • Association with contour-parallel depositional patterns These characteristics reflect the influence of bottom-current controlled sediment transport. 5️⃣ 𝗞𝗲𝘆 𝗜𝗻𝘁𝗲𝗿𝗽𝗿𝗲𝘁𝗮𝘁𝗶𝗼𝗻 𝗖𝗿𝗶𝘁𝗲𝗿𝗶𝗮 To differentiate between these features in seismic data, interpreters often examine:   • Internal reflection patterns   • Geometry and orientation of the mound   • Depositional setting within the basin   • Regional stratigraphic context Reference:https://lnkd.in/daEQ5KZ4