| Title | Tsunami generation from slope failures near/in Kitimat fjord, northwest British Columbia |
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| Author | Huntley, D ;
Bobrowsky, P; Lintern, G |
| Source | 8th International Symposium on Submarine Mass Movements and Their Consequences. Proceedings and Abstracts for Session: Tsunami Generation from Slope Failures. Victoria, May 2018; 2018 p. 1 |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20180461 |
| Meeting | 8th International Symposium on Submarine Mass Movements and Their Consequences. Proceedings and Abstracts for Session: Tsunami Generation from Slope Failures; Victoria, BC; CA; May 7-9, 2018 |
| Document | book |
| Lang. | English |
| Media | paper; digital |
| File format | docx |
| Province | British Columbia |
| NTS | 103H/15; 103I/02 |
| Area | Kitimat; Kitamaat Village; Hartley Bay; Douglas Channel |
| Lat/Long WENS | -129.0000 -128.5000 54.2500 53.7500 |
| Subjects | marine geology; surficial geology/geomorphology; landslides; slope failures; slumps; tsunami; coastal environment; marine sediments; organic deposits; peat; salt marshes; soils; bedrock geology;
structural features; fractures; storms |
| Program | Public Safety
Geoscience Marine Geohazards |
| Released | 2018 05 01 |
| Abstract | There are significant geographic gaps in the geological record of earthquakes, slope failures and tsunamis in the Pacific Northwest, from the northern sector of the Cascadia subduction zone to the
southern sector of the Fairweather-Haida Gwaii transform fault zone. This lack of information is a challenge for communities, government agencies, resource industries and environmental consultants in northwest British Columbia. These stakeholders
require an extended and improved understanding of marine geohazards for evidence-based vulnerability and risk assessments, land management decisions, models of future events and the design of resilient marine infrastructure. Our investigation of salt
marsh peat deposits and forest soils near the coastal communities of Kitimat, Kitamaat and Hartley Bay offers insight into the distribution of tsunami deposits correlated to recent and prehistorical submarine slope failures in the Douglas Channel.
Detailed analyses of sedimentology, radiocarbon dates, fossils, and geochemistry will build on the provisional description of terrestrial soils presented here to establish a postglacial record of tsunami, storm and flood events spanning much of the
Holocene. Small volume debris slides and rock falls do not generate tsunamis of any consequence. In contrast, marine sediments deposited beyond storm berms at the fjord head are a record of local tsunamis generated by large volume marine slumps.
Deep-fractured bedrock mapped upslope from relict submarine features could trigger damaging tsunami waves if rapid failure into the fjord were to occur. These observations suggest only great earthquakes, large landslides and seasonal storms above a
certain threshold volume and impulse energy produce geomorphically significant inundation events. However, even small submarine landslides have tsunamigenic potential in Douglas Channel since they occur in shallow water. This research significantly
extends the geological record of marine geohazard events in the Pacific Northwest. |
| Summary | (Plain Language Summary, not published)
Significant geographic gaps in the geological record of earthquakes, slope failures and tsunamis in the Pacific Northwest present challenges for
communities, government agencies, resource industries and environmental consultants in northwest British Columbia. These stakeholders require an extended and improved understanding of marine geohazards for evidence-based vulnerability and risk
assessments, land management decisions, models of future events and the design of resilient marine infrastructure. Our observations suggest even small submarine landslides have tsunamigenic potential in Douglas Channel since they occur in shallow
water. This research significantly extends the geological record of marine geohazard events in the Pacific Northwest. |
| GEOSCAN ID | 314574 |
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