Seismic and Electrical Geophysical Characterization of an Incipient Coastal Open‐System Pingo: Lagoon Pingo, Svalbard
Abstract Whilst there has been a recent appreciation for the role of open‐system pingos in providing a fluid‐flow conduit through continuous permafrost that enables methane release, the formation and internal structure of these ubiquitous permafrost‐diagnostic landforms remains unclear. Here, we com...
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American Geophysical Union (AGU)
2022
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ftdoajarticles:oai:doaj.org/article:8f45e9272e1c43ea9a4f7550e5deffd6 2023-05-15T13:05:44+02:00 Seismic and Electrical Geophysical Characterization of an Incipient Coastal Open‐System Pingo: Lagoon Pingo, Svalbard Craig P. Hammock Bernd Kulessa John F. Hiemstra Andrew J. Hodson Alun Hubbard 2022-03-01T00:00:00Z https://doi.org/10.1029/2021EA002093 https://doaj.org/article/8f45e9272e1c43ea9a4f7550e5deffd6 EN eng American Geophysical Union (AGU) https://doi.org/10.1029/2021EA002093 https://doaj.org/toc/2333-5084 2333-5084 doi:10.1029/2021EA002093 https://doaj.org/article/8f45e9272e1c43ea9a4f7550e5deffd6 Earth and Space Science, Vol 9, Iss 3, Pp n/a-n/a (2022) open‐system pingo electrical resistivity tomography seismic reflection seismic refraction permafrost methane release Astronomy QB1-991 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.1029/2021EA002093 2022-12-31T03:54:44Z Abstract Whilst there has been a recent appreciation for the role of open‐system pingos in providing a fluid‐flow conduit through continuous permafrost that enables methane release, the formation and internal structure of these ubiquitous permafrost‐diagnostic landforms remains unclear. Here, we combine active‐source seismic measurements with electrical resistivity tomography to investigate the structural and subsurface characteristics of an incipient open‐system pingo actively emitting methane within the glacio‐isostatically uplifting fjord valley of Adventdalen, Svalbard. Wavefront inversion of seismic refractions delineate a spatially heterogeneous active layer, whilst deeper reflections identify the lithological boundaries between marine sediments and underlying shales at ∼68 m depth (p‐wave velocity of ∼1,790 ms−1). Low geometric mean inverted resistivities of 40–150 Ωm highlight the dominance of saline permafrost, whilst elevated resistivities (∼2 kΩm) occur close to the groundwater spring and in heaved areas around the pingo. Based on our results, we speculate that segregation ice dominates the pingo structure, given the absence of a notable resistivity contrast characteristic of injection ice that is typically expected within early open‐system pingo formation, and provides the most plausible geomorphic agent within the local fine‐grained sedimentology. Our results thereby indicate that sediment grain size and moisture availability can provide important controls on pingo formation. This study shows that open‐system pingos in coastal, saline permafrost environments may form differently, with implications for localized permafrost structure, its permeability to underlying gas reservoirs and consequent methane release. Article in Journal/Newspaper Adventdalen Ice open system Pingo permafrost Svalbard Directory of Open Access Journals: DOAJ Articles Svalbard Adventdalen ENVELOPE(16.264,16.264,78.181,78.181) Earth and Space Science 9 3 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
open‐system pingo electrical resistivity tomography seismic reflection seismic refraction permafrost methane release Astronomy QB1-991 Geology QE1-996.5 |
spellingShingle |
open‐system pingo electrical resistivity tomography seismic reflection seismic refraction permafrost methane release Astronomy QB1-991 Geology QE1-996.5 Craig P. Hammock Bernd Kulessa John F. Hiemstra Andrew J. Hodson Alun Hubbard Seismic and Electrical Geophysical Characterization of an Incipient Coastal Open‐System Pingo: Lagoon Pingo, Svalbard |
topic_facet |
open‐system pingo electrical resistivity tomography seismic reflection seismic refraction permafrost methane release Astronomy QB1-991 Geology QE1-996.5 |
description |
Abstract Whilst there has been a recent appreciation for the role of open‐system pingos in providing a fluid‐flow conduit through continuous permafrost that enables methane release, the formation and internal structure of these ubiquitous permafrost‐diagnostic landforms remains unclear. Here, we combine active‐source seismic measurements with electrical resistivity tomography to investigate the structural and subsurface characteristics of an incipient open‐system pingo actively emitting methane within the glacio‐isostatically uplifting fjord valley of Adventdalen, Svalbard. Wavefront inversion of seismic refractions delineate a spatially heterogeneous active layer, whilst deeper reflections identify the lithological boundaries between marine sediments and underlying shales at ∼68 m depth (p‐wave velocity of ∼1,790 ms−1). Low geometric mean inverted resistivities of 40–150 Ωm highlight the dominance of saline permafrost, whilst elevated resistivities (∼2 kΩm) occur close to the groundwater spring and in heaved areas around the pingo. Based on our results, we speculate that segregation ice dominates the pingo structure, given the absence of a notable resistivity contrast characteristic of injection ice that is typically expected within early open‐system pingo formation, and provides the most plausible geomorphic agent within the local fine‐grained sedimentology. Our results thereby indicate that sediment grain size and moisture availability can provide important controls on pingo formation. This study shows that open‐system pingos in coastal, saline permafrost environments may form differently, with implications for localized permafrost structure, its permeability to underlying gas reservoirs and consequent methane release. |
format |
Article in Journal/Newspaper |
author |
Craig P. Hammock Bernd Kulessa John F. Hiemstra Andrew J. Hodson Alun Hubbard |
author_facet |
Craig P. Hammock Bernd Kulessa John F. Hiemstra Andrew J. Hodson Alun Hubbard |
author_sort |
Craig P. Hammock |
title |
Seismic and Electrical Geophysical Characterization of an Incipient Coastal Open‐System Pingo: Lagoon Pingo, Svalbard |
title_short |
Seismic and Electrical Geophysical Characterization of an Incipient Coastal Open‐System Pingo: Lagoon Pingo, Svalbard |
title_full |
Seismic and Electrical Geophysical Characterization of an Incipient Coastal Open‐System Pingo: Lagoon Pingo, Svalbard |
title_fullStr |
Seismic and Electrical Geophysical Characterization of an Incipient Coastal Open‐System Pingo: Lagoon Pingo, Svalbard |
title_full_unstemmed |
Seismic and Electrical Geophysical Characterization of an Incipient Coastal Open‐System Pingo: Lagoon Pingo, Svalbard |
title_sort |
seismic and electrical geophysical characterization of an incipient coastal open‐system pingo: lagoon pingo, svalbard |
publisher |
American Geophysical Union (AGU) |
publishDate |
2022 |
url |
https://doi.org/10.1029/2021EA002093 https://doaj.org/article/8f45e9272e1c43ea9a4f7550e5deffd6 |
long_lat |
ENVELOPE(16.264,16.264,78.181,78.181) |
geographic |
Svalbard Adventdalen |
geographic_facet |
Svalbard Adventdalen |
genre |
Adventdalen Ice open system Pingo permafrost Svalbard |
genre_facet |
Adventdalen Ice open system Pingo permafrost Svalbard |
op_source |
Earth and Space Science, Vol 9, Iss 3, Pp n/a-n/a (2022) |
op_relation |
https://doi.org/10.1029/2021EA002093 https://doaj.org/toc/2333-5084 2333-5084 doi:10.1029/2021EA002093 https://doaj.org/article/8f45e9272e1c43ea9a4f7550e5deffd6 |
op_doi |
https://doi.org/10.1029/2021EA002093 |
container_title |
Earth and Space Science |
container_volume |
9 |
container_issue |
3 |
_version_ |
1766392476659089408 |