Improvements in the regional earthquake focal mechanism catalogue for southwestern Yukon

Earthquake source characteristics provide a valuable constraint on fault behaviour, crustal stress, and regional plate tectonics. In southwestern Yukon, a region of complex active tectonics, studies of earthquake sources have historically been limited by sparse seismic network coverage. In this work, we leverage recent improvements in station coverage to estimate focal mechanisms for small and moderate-magnitude (M ≥ 2.0) earthquakes from P-wave first-motion polarity data. We invert these data using a probabilistic method that rigorously quantifies mechanism uncertainties. We present preliminary solutions for 363 events, which improve the spatial coverage of the focal mechanism catalogue for this region. We observe contrasting P-axis orientations for events on either side of the Fairweather fault. For events within southwestern Yukon, the distribution of faulting mechanism types and P-axis orientations are relatively consistent. Our focal mechanism solutions support the existence of an unmapped fault south of the Duke River fault. Finally, our results provide a valuable input for subsequent detailed analysis of crustal stress throughout the region.

Data and Resources

Additional Info

Field Value
Source
Version
Author
Author Email
Maintainer
Maintainer Email
Data Level
Agreement Required
Purpose Constraints
Redistribution Allowed
AI Training Allowed
Data Steward
Title (French)
Update Frequency unknown
Geographic Scope []
Criticality Level []
Sensitivity Level unrestricted
Language
Contact Person {"en": "Yukon Geological Survey", "fr": "Yukon Geological Survey"}
Contact Email eservices@gov.yk.ca
Data Dictionary []
Open Canada Date Published 2023-01-19 00:00:00
Open Canada Date Modified
Open Canada Subject ["science_and_technology"]
Open Canada Keywords {"en": ["ygs-import", "ygs-import-20250711", "ygs-publications", "yukon-geological-survey"], "fr-t-en": ["importation d'ygs", "ygs-import-20250711", "publications de l'YGS", "enquête géologique du yukon"]}
Open Canada Collection federated
Principal Organization
Reference Data
Official Source