@article {2621,
	title = {Paleoseismic Results from the Alpine Site, Wasatch Fault Zone: Timing and Displacement Data for Six Holocene Earthquakes at the Salt Lake City{\textendash}Provo Segment Boundary},
	journal = {Bulletin of the Seismological Society of America},
	year = {2018},
	month = {Feb-10-2018},
	abstract = {To improve the characterization of Holocene earthquakes on the Wasatch fault zone (WFZ), we conducted light detection and ranging (lidar)-based neotectonic mapping and excavated a paleoseismic trench across an 8-m-high fault scarp near Alpine, Utah, located <1  km south of the boundary between the Salt Lake City and Provo segments (SLCS and PS). We document evidence for six paleoearthquakes (AL6{\textendash}AL1) from scarp-derived colluvial wedges and crosscutting relations. A ground-penetrating radar survey across the scarp resolved fault-zone width, but not paleoearthquake stratigraphy. Bayesian (OxCal) modeling of 13 radiocarbon and 13 optically stimulated luminescence ages indicates that six earthquakes occurred \~{}6.2{\textendash}0.4  ka. Interseismic recurrence ranges from 0.2 to 1.8 ky (mean 1.2 ky). We estimate 6.5{\textpm}0.7  m of cumulative vertical tectonic displacement across the >=14-m-wide fault zone used near-field observations of scarp-derived colluvial-wedge thicknesses, antithetic faulting, and graben backtilting. This is similar to our independent estimate of 6.5{\textpm}0.5  m using far-field observations of the offset ground surface and correlation of alluvial-fan stratigraphy across the WFZ. These results suggest that colluvial-wedge thickness at the Alpine site approximates one-half the original west-facing fault scarp height. Per-event vertical displacements range from 0.8 to 1.2 m (mean 1.1 m), which we use to estimate surface rupture lengths that may exceed 50 km from earthquakes as large as moment magnitude (Mw) \~{}7.0. The late Holocene average vertical slip rate is 0.9  mm/yr (0.7{\textendash}1.2  mm/yr range). Earthquake frequency has increased in the past \~{}1  ky, whereas displacement per event has been similar for the past \~{}6  ky, suggesting that strain accumulation is not the sole factor that controls the frequency and size of earthquakes at the SLCS{\textendash}PS segment boundary. These findings can be used for a more nuanced characterization of earthquakes at the SLCS{\textendash}PS boundary and improve earthquake hazard assessments along the Wasatch Front.},
	issn = {0037-1106},
	doi = {10.1785/0120160358},
	url = {https://pubs.geoscienceworld.org/ssa/bssa/article/556954/Paleoseismic-Results-from-the-Alpine-Site-Wasatch},
	author = {Bennett, S. E. K. and DuRoss, C. B. and Gold, R. D. and Briggs, R. W. and Personius, S. F. and Reitman, N. G. and Devore, J. R. and Hiscock, A. I. and Mahan, S. A. and Gray, H. J. and Gunnarson, S. and Stephenson, W. J. and Pettinger, E. and Odum, J. K.}
}
@article {2592,
	title = {Holocene earthquakes and right-lateral slip on the left-lateral Darrington-Devils Mountain fault zone, northern Puget Sound, Washington},
	journal = {Geosphere},
	volume = {10},
	year = {2014},
	month = {Jan-12-2014},
	pages = {1482 - 1500},
	abstract = {Sources of seismic hazard in the Puget Sound region of northwestern Washington include deep earthquakes associated with the Cascadia subduction zone, and shallow earthquakes associated with some of the numerous crustal (upper-plate) faults that crisscross the region. Our paleoseismic investigations on one of the more prominent crustal faults, the Darrington{\textendash}Devils Mountain fault zone, included trenching of fault scarps developed on latest Pleistocene glacial sediments and analysis of cores from an adjacent wetland near Lake Creek, 14 km southeast of Mount Vernon, Washington. Trench excavations revealed evidence of a single earthquake, radiocarbon dated to ca. 2 ka, but extensive burrowing and root mixing of sediments within 50{\textendash}100 cm of the ground surface may have destroyed evidence of other earthquakes. Cores in a small wetland adjacent to our trench site provided stratigraphic evidence (formation of a laterally extensive, prograding wedge of hillslope colluvium) of an earthquake ca. 2 ka, which we interpret to be the same earthquake documented in the trenches. A similar colluvial wedge lower in the wetland section provides possible evidence for a second earthquake dated to ca. 8 ka. Three-dimensional trenching techniques revealed evidence for 2.2 {\textpm} 1.1 m of right-lateral offset of a glacial outwash channel margin, and 45{\textendash}70 cm of north-side-up vertical separation across the fault zone. These offsets indicate a net slip vector of 2.3 {\textpm} 1.1 m, plunging 14{\textdegree} west on a 286{\textdegree}-striking, 90{\textdegree}-dipping fault plane. The dominant right-lateral sense of slip is supported by the presence of numerous Riedel R shears preserved in two of our trenches, and probable right-lateral offset of a distinctive bedrock fault zone in a third trench. Holocene north-side-up, right-lateral oblique slip is opposite the south-side-up, left-lateral oblique sense of slip inferred from geologic mapping of Eocene and older rocks along the fault zone. The cause of this slip reversal is unknown but may be related to clockwise rotation of the Darrington{\textendash}Devils Mountain fault zone into a position more favorable to right-lateral slip in the modern N-S compressional stress field.},
	doi = {10.1130/GES01067.1},
	url = {https://pubs.geoscienceworld.org/geosphere/article/10/6/1482-1500/132254},
	author = {Personius, S. F. and Briggs, R. W. and Nelson, A. R. and Schermer, E. R. and Maharrey, J. Z. and Sherrod, B. L. and Spaulding, S. A. and Bradley, L.-A.}
}
