| Titre | Structure and kinematics of the Eastern Denali fault from drone and crewed airborne lidar surveys |
| |
| Auteur | Finley, T; Salomon, G; Stephen, R; Nissen, E; Cassidy, J F ; Menounos, B |
| Source | Seismological Society of America, Proceedings vol. 93, no. 28, 2022 p. 1298-1299 |
| Image |  |
| Année | 2022 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20210549 |
| Éditeur | Seismological Society of America |
| Réunion | Seismological Society of America Technical Sessions; Bellevue; US; avril 19-23, 2022 |
| Document | publication en série |
| Lang. | anglais |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Yukon |
| Sujets | Sciences et technologie |
| Programme | Géoscience pour la sécurité publique Risques géologique du tremblement de terre |
| Diffusé | 2022 04 01 |
| Résumé | (disponible en anglais seulement)
The Eastern Denali fault (EDF) in the Yukon has not, until now, been widely covered by lidar data, and interpretations of its kinematics and paleoseismic record
have consequently been subject to uncertainty. We present new lidar data collected with a rotary-wing drone over several segments of the EDF on the southwest side of Kluane Lake, which enabled the production of Digital Terrain Models (DTMs) with ~30
cm spatial resolution. We also present new lidar data collected with a crewed fixed-wing aircraft between the Slims and Duke rivers. These datasets offer a considerable increase in spatial resolution and canopy penetration compared to existing
spaceborne and airborne photogrammetric Digital Surface Models (DSMs) of the EDF. We re-map the EDF in detail and find several locations where previous DSMs did not accurately portray the fault surface trace. The lidar data also provide improved
estimates of fault offset and kinematics: stream channels and hill slopes that cross the fault at high angles indicate dextral offsets of 5-75 m. Vertical separation ranges from 0-20 m, varying between NE- and SW-side up. Offset across the fault
varies considerably between geomorphological surfaces of different ages (i.e., glacial drift vs. younger fluvial terraces), suggesting that the lidar data may be able to distinguish multiple slip events. The higher spatial resolution achieved by the
drone lidar reveals possible E-W-trending compressional structures (fault tips or fold axes) on a series of sediment mounds along the fault. These short-wavelength features are not visible in the crewed airborne lidar. Drone lidar is a relatively new
technology, and this study allows for a comparison of the costs and benefits of drone versus crewed airborne lidar acquisition for active tectonics research; the drone is less expensive to deploy and offers a substantial increase in point density,
but covers a smaller area and is subject to several practical and regulatory constraints. (Invited Contribution) |
| Sommaire | (Résumé en langage clair et simple, non publié)
De nouveaux ensembles de données lidar sont analysés pour fournir de nouvelles contraintes sur la tectonique et le mouvement le long de la zone
de faille Eastern Denali au Yukon. Nous trouvons des preuves d'un mouvement substantiel le long de cette zone de faille et des indications préliminaires que ces nouvelles données peuvent distinguer plusieurs événements de glissement. Ces nouvelles
informations permettront d'améliorer les évaluations des risques sismiques au Yukon. En tant que l'une des premières études détaillées utilisant une technologie relativement nouvelle (Drone lidar), cette étude permet de comparer les coûts et les
avantages de l'acquisition d'un drone par rapport à l'acquisition d'un lidar aéroporté avec équipage pour la recherche en tectonique active. |
| GEOSCAN ID | 329446 |
|
|