| Title | Structure and kinematics of the Eastern Denali fault from drone and crewed airborne lidar surveys |
| |
| Author | 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 |  |
| Year | 2022 |
| Alt Series | Natural Resources Canada, Contribution Series 20210549 |
| Publisher | Seismological Society of America |
| Meeting | Seismological Society of America Technical Sessions; Bellevue; US; April 19-23, 2022 |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Yukon |
| Area | Canada |
| Subjects | Science and Technology; Eastern Denali Fault |
| Program | Public Safety Geoscience Assessing Earthquake Geohazards |
| Released | 2022 04 01 |
| Abstract | 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) |
| Summary | (Plain Language Summary, not published)
New lidar data sets are analysed to provide new constraints on the tectonics and movement along the Eastern Denali fault zone in the Yukon. We find
evidence for substantial movement along this fault zone, and preliminary indications that these new data can distinguish multiple slip events. This new information will improve assessments of earthquake hazards in the Yukon. As one of the first
detailed studies using a relatively new technology (Drone lidar), this study allows for a comparison of the costs and benefits of drone versus crewed airborne lidar acquisition for active tectonics research. |
| GEOSCAN ID | 329446 |
|
|