Submarine permafrost depth from ambient seismic noise

Overduin, Paul; Haberland, Christian; Ryberg, Trond; Kneier, Fabian; Jacobi, Tim; Grigoriev, Mikhail N.; Ohrnberger, Matthias

doi:10.1002/2015gl065409

Cited by 38 publications

(24 citation statements)

References 54 publications

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“…However, although the successful applications, the theoretical interpretation of the H/V function is still a matter of debate, mainly related to the unknown ambient vibration wavefield composition [ Lunedei and Malischewsky , ; Overduin et al ., ]. Three main physical interpretations of the H/V have been proposed in the literature [ Piña‐Flores et al ., ].…”

Section: Methods and Data Acquisitionmentioning

confidence: 99%

Geometry and evolution of a fault‐controlled Quaternary basin by means of TDEM and single‐station ambient vibration surveys: The example of the 2009 L'Aquila earthquake area, central Italy

et al. 2017

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We applied a joint survey approach integrating time domain electromagnetic soundings and single‐station ambient vibration surveys in the Middle Aterno Valley (MAV), an intermontane basin in central Italy and the locus of the 2009 L'Aquila earthquake. By imaging the buried interface between the infilling deposits and the top of the pre‐Quaternary bedrock, we reveal the 3‐D basin geometry and gain insights into the long‐term basin evolution. We reconstruct a complex subsurface architecture, characterized by three main depocenters separated by thresholds. Basin infill thickness varies from ~200–300 m in the north to more than 450 m to the southeast. Our subsurface model indicates a strong structural control on the architecture of the basin and highlights that the MAV experienced considerable modifications in its configuration over time. The buried shape of the MAV suggests a recent and still ongoing predominant tectonic control by the NW‐SE trending Paganica‐San Demetrio Fault System (PSDFS), which crosscuts older ~ENE and NNE trending extensional faults. Furthermore, we postulate that the present‐day arrangement of the PSDFS is the result of the linkage of two previously isolated fault segments. We provide constraints on the location of the southeastern boundary of the PSDFS, defining an overall ~19 km long fault system characterized by a considerable seismogenetic potential and a maximum expected magnitude larger than M 6.5. This study emphasizes the benefit of combining two easily deployable geophysical methods for reconstructing the 3‐D geometry of a tectonically controlled basin. Our joint approach provided us with a consistent match between these two independent estimations of the basin substratum depth within 15%.

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Section: Methods and Data Acquisitionmentioning

confidence: 99%

Geometry and evolution of a fault‐controlled Quaternary basin by means of TDEM and single‐station ambient vibration surveys: The example of the 2009 L'Aquila earthquake area, central Italy

et al. 2017

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“…Lastly, arrays of multiple seismic stations could provide insights into the spatial variations of subsurface properties and alterations. Recent studies have demonstrated the opportunities and challenges for passive seismic monitoring of permafrost environments through horizontal‐to‐vertical spectral ratios (Abbott et al, ; Köhler & Weidle, ; Kula et al, ; Overduin et al, ). To date, using ambient noise for seismic interferometry has yet to be fully investigated for spatiotemporal monitoring of permafrost and active‐layer processes.…”

Section: Introductionmentioning

confidence: 99%

Insights Into Permafrost and Seasonal Active‐Layer Dynamics From Ambient Seismic Noise Monitoring

et al. 2019

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Widespread permafrost thaw in response to changing climate conditions has the potential to dramatically impact ecosystems, infrastructure, and the global carbon budget. Ambient seismic noise techniques allow passive subsurface monitoring that could provide new insights into permafrost vulnerability and active-layer processes. Using nearly 2 years of continuous seismic data recorded near Fairbanks, Alaska, we measured relative velocity variations that showed a clear seasonal cycle reflecting active-layer freeze and thaw. Relative to January 2014, velocities increased up to 3% through late spring, decreased to −8% by late August, and then gradually returned to the initial values by the following winter. Velocities responded rapidly (over~2 to 7 days) to discrete hydrologic events and temperature forcing and indicated that spring snowmelt and infiltration events from summer rainfall were particularly influential in propagating thaw across the site. Velocity increases during the fall zero-curtain captured the refreezing process and incremental ice formation. Looking across multiple frequency bands (3-30 Hz), negative relative velocities began at higher frequencies earlier in the summer and then shifted lower when active-layer thaw deepened, suggesting a potential relationship between frequency and thaw depth; however, this response was dependent on interstation distance. Bayesian tomography returned 2-D time-lapse images identifying zones of greatest velocity reduction concentrated in the western side of the array, providing insight into the spatial variability of thaw progression, soil moisture, and drainage. This study demonstrates the potential of passive seismic monitoring as a new tool for studying site-scale active-layer and permafrost thaw processes at high temporal and spatial resolution.Plain Language Summary Seismic vibrations in the ground generated by background sources of noise (vehicle traffic, wind, ocean waves, etc.) occur continuously and provide a way to monitor environmental changes with time. We used 2 years of noise data to study belowground changes in Alaska, where the upper layer of soil freezes and thaws seasonally and deeper soil (permafrost) remains frozen year-round. Warming temperatures may alter the depth of thaw each summer and degrade permafrost, which could significantly impact ecosystems and infrastructure. Our results show a clear seasonal pattern corresponding with the timing of soil freeze/thaw. Vibrations traveled at the fastest speeds during early spring, indicating frozen soil with ice. Speeds became slower following snowmelt and warmer temperatures in late spring and early summer. Strong decreases in seismic-wave speeds corresponded with heavy rains and warm temperatures, suggesting warm water percolating downward through the soil induced more thaw. Speeds gradually increased again through the fall during ice formation. We also mapped where soil changes occurred most strongly and thereby revealed spatial differences in thaw depth and soil moisture across the site. This work dem...

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“…Alternative geophysical methods like ground‐penetrating radar have proven to be effective at mapping taliks below freshwater grounded ice zones (Stevens et al, ) but are not suited for highly electrically conductive saltwater (Annan, ). While passive seismic has been recently used to map the depth to ice‐bearing subsea permafrost (Overduin et al, ), it is a technique still in development and not practical to achieve the desired spatial resolution of this study. Active seismic methods have been used to map the depth to deep ice‐bearing subsea permafrost offshore in the Laptev Sea (Hinz et al, ) but are less effective techniques in shallow coastal waters and are not sensitive to subtle changes of salt in the porewater of frozen sediment.…”

Section: Introductionmentioning

confidence: 99%

Heat and Salt Flow in Subsea Permafrost Modeled with CryoGRID2

et al. 2019

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Thawing of subsea permafrost can impact offshore infrastructure, affect coastal erosion, and release permafrost organic matter. Thawing is usually modeled as the result of heat transfer, although salt diffusion may play an important role in marine settings. To better quantify nearshore subsea permafrost thawing, we applied the CryoGRID2 heat diffusion model and coupled it to a salt diffusion model. We simulated coastline retreat and subsea permafrost evolution as it develops through successive stages of a thawing sequence at the Bykovsky Peninsula, Siberia. Sensitivity analyses for seawater salinity were performed to compare the results for the Bykovsky Peninsula with those of typical Arctic seawater. For the Bykovsky Peninsula, the modeled ice‐bearing permafrost table (IBPT) for ice‐rich sand and an erosion rate of 0.25 m/year was 16.7 m below the seabed 350 m offshore. The model outputs were compared to the IBPT depth estimated from coastline retreat and electrical resistivity surveys perpendicular to and crossing the shoreline of the Bykovsky Peninsula. The interpreted geoelectric data suggest that the IBPT dipped to 15–20 m below the seabed at 350 m offshore. Both results suggest that cold saline water forms beneath grounded ice and floating sea ice in shallow water, causing cryotic benthic temperatures. The freezing point depression produced by salt diffusion can delay or prevent ice formation in the sediment and enhance the IBPT degradation rate. Therefore, salt diffusion may facilitate the release of greenhouse gasses to the atmosphere and considerably affect the design of offshore and coastal infrastructure in subsea permafrost areas.

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Submarine permafrost depth from ambient seismic noise

Cited by 38 publications

References 54 publications

Geometry and evolution of a fault‐controlled Quaternary basin by means of TDEM and single‐station ambient vibration surveys: The example of the 2009 L'Aquila earthquake area, central Italy

Geometry and evolution of a fault‐controlled Quaternary basin by means of TDEM and single‐station ambient vibration surveys: The example of the 2009 L'Aquila earthquake area, central Italy

Insights Into Permafrost and Seasonal Active‐Layer Dynamics From Ambient Seismic Noise Monitoring

Heat and Salt Flow in Subsea Permafrost Modeled with CryoGRID2

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