The MacKenzie Mountains, Northwest Territories, earthquake sequence of 1953 to 1957
Bibliographic record
Abstract
The northern Canadian Cordillera is a region of intense, poorly understood seismicity. Between 1953 and 1957, five moderate to large earthquakes (M5.8–6.4) struck the remote northern MacKenzie Mountains. We utilize historical seismograms, felt reports, and other information to define the epicentres, focal depths, magnitudes, and focal mechanisms of this previously unstudied earthquake sequence. The 1953 and 1955 earthquakes were felt (up to intensity V) to distances of 230–280 km. Magnitudes (Mw) were determined at 6.3 and 6.4, respectively. Epicentres were relocated using path corrections obtained from well-recorded modern earthquakes (M4.5–5) in this region. The relocated epicentres are distributed in an east-southeast–west-northwest direction over ∼45 km. The 1955 mainshock and largest aftershock are separated by ∼20 km, with the aftershock located north-northeast of the mainshock. The 1957 (M5.8) earthquake is located a similar distance and direction from the 1956 (M6.1) earthquake, suggesting that it may be an aftershock of that event. Focal mechanisms and depths were determined using body wave modelling. Depths ranged from 9 to 15 km, and focal mechanisms show thrust faulting along either a north-northeast-plane or a south-southwest-dipping plane. The orientation of the east-southeast–west-northwest striking nodal plane is consistent with the distribution of epicentres and the regional geology. The north-northeast–south-southwest striking, shallow-dipping P-axes are consistent with the regional stress field. This study reveals numerous similarities with the 1985–1988 Nahanni earthquake sequence, including shallow, thrust faulting, earthquakes over several years, and likely caused by stresses transmitted from the plate boundary (700+ km to the west), activating favourably oriented thrust faults.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".