| Title | Microseismicity and Tectonics of Southwest Yukon Territory, Canada, Using a Local Dense Seismic Array |
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| Author | Meighan, L N; Cassidy, J F ; Mazzotti, S; Pavlis, G L |
| Source | Bulletin of the Seismological Society of America vol. 103, no. 6, 2013 p. 3341-3346, https://doi.org/10.1785/0120130068 |
| Image |  |
| Year | 2013 |
| Alt Series | Earth Sciences Sector, Contribution Series 20130008 |
| Publisher | Seismological Society of America (SSA) |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Yukon; British Columbia |
| NTS | 104L; 104M; 114I; 114J; 114O; 114P; 105D; 105E; 115A; 115B; 115C; 115F; 115G; 115H |
| Area | Alaska; Canada; United States of America |
| Lat/Long WENS | -142.0000 -134.0000 63.0000 58.0000 |
| Subjects | geophysics; tectonics; seismicity; seismic interpretations; tectonic interpretations; tectonic setting; tectonic environments; structural features; faults; Yakutat Block; Duke River Fault; Denali
Fault |
| Illustrations | location maps; bar graphs |
| Program | Public Safety Geoscience Targeted Hazard Assessments in Western Canada |
| Released | 2013 10 29 |
| Abstract | The objective of this paper is to provide a better understanding of the relationship between the microseismicity, active tectonics, and crustal structures in the southwest Yukon Territory, Canada, in
order to improve seismic-hazard assessments in this region.We utilize data from a new dense seismic array that was deployed in the southwest Yukon in the summer of 2010. Data from the new seismic array significantly improve the magnitude completeness
level in the region from ML 3.0 to 1.0. We analyze 980 events ranging in magnitudes from ML 0.2 to 4.7, at depths from 0 to 35 km. Relocation analysis using the progressive multiple event location shows that seismicity is concentrated in four main
areas: (1) Yakutat block northern boundary - Fairweather fault, (2) Duke River fault, (3) southern Denali fault, and (4) a previously unrecognized northeast trending cluster that may highlight a previously unknown active fault. This cluster may
contribute to stress and strain transfer inland from the Yakutat block region. |
| Summary | (Plain Language Summary, not published)
Our understanding of earthquake hazards in the southwest Yukon has been limited by a lack of data - specifically, few seismic stations at relatively
large distances. With the deployment of a dense array of seismic stations in the vicinity of the Denali Fault in the summer of 2010, we are able to now locate much smaller earthquakes (to M 1) and determine earthquake depths. We located nearly 1000
earthquakes over a 15-month period and were able to determine precise earthquake locations and depths. These new results show a concentration of earthquakes along the Duke River Fault system and have highlighted a narrow NE-trending band of
seismicity on a near-vertical structure that was previously unknown. Our new earthquake constraints (and especially focal depths) provide critical new information for modelling GPS data and improving earthquake hazard assessments in this
region. |
| GEOSCAN ID | 292508 |
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