| Autor: |
Nicovich, Sylvia R., DuRoss, Christopher B., Thompson Jobe, Jessica A., Rodysill, Jessica R., Briggs, Richard W., Hatem, Alexandra E., Tan, Madeleine M., Gavillot, Yann, Lindberg, Noah S., Strickland, Laura E., Padgett, Jason S. |
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| Zdroj: |
Geophysical Research Letters; Nov2024, Vol. 51 Issue 22, p1-11, 11p |
| Abstrakt: |
We investigate a shallow lake basin for evidence of a large historic intraplate earthquake in western North America. Henrys Lake, Idaho is an atypical candidate for lacustrine paleoseismic study given its shallow depth (∼7 m) and low relief (≤2° slopes). Here, we test the earthquake‐recording capacity of this basin type by showing sedimentological evidence of the 1959 M7.3 Hebgen Lake earthquake within sediment cores, using anthropogenically produced 137Cs activity to constrain timing. In addition to expanding the morphologic range of basins targeted for lacustrine paleoseismic studies, this work has implications for sediment response in dam‐enhanced basins. Lack of sedimentological evidence for other earthquakes coupled with radiocarbon chronology reveals that the 1959 event is the only clearly recorded earthquake within Henrys Lake since the mid‐Holocene. Henrys Lake offers a proxy for paleo‐earthquake signatures within similar lacustrine environments and underscores the importance of further paleoseismic studies in the region. Plain Language Summary: Earthquake‐triggered sedimentation within lake systems is not simple to interpret. There are many uncertainties because other earth processes beyond earthquakes can generate similar deposits. We test whether we can observe the 1959 M7.3 Hebgen Lake earthquake within nearby Henrys Lake, Idaho. Henrys Lake is distinct from most lakes studied for earthquakes, with a shallow depth and low‐angle margin slopes. We extracted sediment cores from Henrys Lake that reveal evidence of the 1959 Hebgen Lake earthquake and estimate deposit timing with radiometric techniques. The Henrys Lake record opens opportunities for similar lake systems that may be more readily available than the traditional basins targeted for this type of study and can inform ground shaking activity within the region. Key Points: Sediment cores from Henrys Lake record ground shaking produced from the 1959 M7.3 Hebgen Lake earthquakeHenrys Lake sediment cores do not record shaking‐induced sedimentation from ∼4.7 ka until 1959Lacustrine sediments in shallow, low‐relief, intraplate basins can record earthquake shaking [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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