@article{RegallaKirbyFisheretal.2013,
  author    = {Regalla, Christine and Kirby, Eric and Fisher, Donald and Bierman, Paul R.},
  title     = {Active forearc shortening in Tohoku, Japan - constraints on fault geometry from erosion rates and fluvial longitudinal profiles},
  series = {Geomorphology : an international journal on pure and applied geomorphology},
  volume    = {195},
  journal   = {Geomorphology : an international journal on pure and applied geomorphology},
  number    = {8},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0169-555X},
  doi       = {10.1016/j.geomorph.2013.04.029},
  pages     = {84 -- 98},
  year      = {2013},
  abstract  = {Convexities in the longitudinal profiles of actively incising rivers are typically considered to represent the morphologic signal of a transient response to external perturbations in tectonic or climatic forcing. Distinguishing such knickzones from those that may be anchored to the channel network by spatial variations in rock uplift, however, can be challenging. Here, we combine stream profile analysis, Be-10 watershed-averaged erosion rates, and numerical modeling of stream profile evolution to evaluate whether knickzones in the Abukuma massif of northeast Japan represent a temporal or spatial change in rock uplift rate in relation to forearc shortening. Knickzones in channels that drain the eastern flank of the Abukuma massif are characterized by breaks in slope-area scaling and separate low-gradient, alluvial upper-channel segments from high-gradient, deeply-incised lower channel segments. Average erosion rates inferred from Be-10 concentrations in modern sediment below knickzones exceed erosion rates above knickzones by 20-50\%. Although profile convexities could be interpreted as a transient response to an increase in rock uplift rate associated with slip on the range-bounding fault, geologic constraints on the initiation of fault slip and the magnitude of displacement cannot be reconciled with a recent, spatially uniform increase in slip rate. Rather, we find that knickzone position, stream profile gradients, and basin averaged erosion rates are best explained by a relatively abrupt spatial increase in uplift rate localized above a flat-ramp transition in the fault system. These analyses highlight the importance of considering spatially non-uniform uplift in the interpretation of stream profile evolution and demonstrate that the adjustment of river profiles to fault displacement can provide constraints on fault geometry in actively eroding landscapes. (C) 2013 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{MillerSakKirbyetal.2013,
  author    = {Miller, Scott R. and Sak, Peter B. and Kirby, Eric and Bierman, Paul R.},
  title     = {Neogene rejuvenation of central appalachian topography evidence for differential rock uplift from stream profiles and erosion rates},
  series = {Earth \& planetary science letters},
  volume    = {369},
  journal   = {Earth \& planetary science letters},
  number    = {2},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0012-821X},
  doi       = {10.1016/j.epsl.2013.04.007},
  pages     = {1 -- 12},
  year      = {2013},
  abstract  = {The persistence of topography within ancient orogens remains one of the outstanding questions in landscape evolution. In the eastern North American Appalachians, this question is manifest in the outstanding problem of whether topographic relief is in a quasi-equilibrium state, decaying slowly over many millennia, or whether relief has increased during the late Cenozoic. Here we present quantitative geomorphic data from the nonglaciated portion of the Susquehanna River drainage basin that provide insight into these end-member models. Analysis of channel profiles draining upland catchments in the northern Valley and Ridge, Appalachian Plateau, Blue Ridge, and Piedmont provinces reveals that a large number of streams have well defined knickpoints clustered at 300-600 m elevation but not systematically associated with transitions from weak to resistant substrate. Cosmogenic Be-10 inventories of modern stream sediment indicate that erosion rates are spatially variable, ranging from similar to 5-30 m/Myr above knickpoints to similar to 50-100 m/Myr below knickpoints. Overall, channel gradients, normalized for drainage area, scale linearly with catchment-averaged erosion rates. Collectively, regionally consistent spatial relationships among erosion rate, channel steepness, and knickpoints reveal an ongoing wave of transient channel adjustment to a change in relative base level. Reconstructions of relict channel profiles above knickpoints suggest that higher rates of incision are associated with similar to 100-150 m of relative base level fall that accompanied epierogenic rock uplift rather than a change to a more erosive climate or drainage reorganization. Channel response timescales imply that the onset of relative base level change predates similar to 3.5 Ma and may have begun as early as similar to 15 Ma. We suggest that adjustment of the channel network was likely driven by changes in mantle dynamics along the eastern seaboard of North America during the Neogene.},
  language  = {en}
}
@article{KirbyHarkins2013,
  author    = {Kirby, Eric and Harkins, Nathan},
  title     = {Distributed deformation around the eastern tip of the Kunlun fault},
  series = {INTERNATIONAL JOURNAL OF EARTH SCIENCES},
  volume    = {102},
  journal   = {INTERNATIONAL JOURNAL OF EARTH SCIENCES},
  number    = {7},
  publisher = {SPRINGER},
  address   = {NEW YORK},
  issn      = {1437-3254},
  doi       = {10.1007/s00531-013-0872-x},
  pages     = {1759 -- 1772},
  year      = {2013},
  abstract  = {Whether active strain within the Indo-Asian collision zone is primarily localized along major strike-slip fault systems or is distributed throughout the intervening crust between faults remains uncertain. Despite refined estimates of slip rates along many of the major fault zones, relatively little is known about how displacement along these structures is accommodated at fault terminations. Here, we show that a systematic decrease in left-lateral slip rates along the eastern similar to 200 km of the Kunlun fault, from > 10 mm/year to < 1 mm/year, is coincident with high topography in the Anyemaqen Shan and with a broad zone of distributed shear and clockwise vorticity within the Tibetan Plateau. Geomorphic analysis of river longitudinal profiles, coupled with inventories of cosmogenic radionuclides in fluvial sediment, reveal correlated variations in fluvial relief and erosion rate across the Anyemaqen Shan that reflect ongoing differential rock uplift across the range. Our results imply that the termination of the Kunlun fault system is accommodated by a combination of distributed crustal thickening and by clockwise rotation of the eastern fault segments.},
  language  = {en}
}