Thick deposits preserved in deep valleys in the Indus, Gilgit, and Hunza River Basins, and a variety of dates, allow new definition of Quaternary events in the Karakoram and Nanga ParbatHimalaya. An unusually long record for an actively eroding high mountain area is recognized in three major episodes of glaciation during Pleistocene time. An early glaciation is represented by the indurated lower Jalipur tillites and heterogeneous upper Jalipur valley-fill sedimentary rock younger than 1 to 2 Ma, which are folded, overturned, or overridden by rapid movement on the dextral-reverse Raikot fault. This is associated with high overall uplift rates of the Nanga Parbat-Haramosh massif during late Cenozoic time. The middle glaciation is represented by two tills intercalated within variable sediments, including thick lacustrine units dipping as much as 43° along the fault. The Indus-Shatial till of the early middle glaciation records the farthest advance of Pleistocene glaciers down the Indus River valley. The last glaciation apparently occurred after about 140,000 yr ago and consists of three to four or more separate advances, as recorded by morainic topography. The most prominent of these is the Dianyor moraine near Gilgit, which was produced by a major longitudinal glacier. Near Haramosh and downstream at Nanga Parbat, Shatial, and elsewhere, transverse glaciers blocked the Indus River to produce lake deposits now dipping as much as 6° near the fault. Catastrophic floods from failure of the ice dams, and possibly landslide dams as well, emplaced some Punjab erratics and sediments that may have been reworked into loesses and other sediments at the mountain front.on July 23, 2015 specialpapers.gsapubs.org Downloaded from
Metropolitan Portland, Oregon, USA, lies within a small Neogene to Holocene basin in the forearc of the Cascadia subduction system. Although the basin owes its existence and structural development to its convergent-margin tectonic setting, the stratigraphic architecture of basin-fill deposits chiefly reflects its physiographic position along the lower reaches of the continental-scale Columbia River system. As a result of this globally unique setting, the basin preserves a complex record of aggradation and incision in response to distant as well as local tectonic, volcanic, and climatic events. Voluminous flood basalts, continental and locally derived sediment and volcanic debris, and catastrophic flood deposits all accumulated in an area influenced by contemporaneous tectonic deformation and variations in regional and local base level.
Previous pedestrian evacuation modeling for tsunamis has not considered variable wave arrival times or critical junctures (e.g., bridges), and did not effectively communicate multiple evacuee travel speeds. We summarize an approach that identifies evacuation corridors, recognizes variable wave arrival times, and produces a map of minimum pedestrian travel speeds to reach safety, termed a ''beat-the-wave'' (BTW) evacuation analysis. We demonstrate the improved approach by evaluating difficulty of pedestrian evacuation of Seaside, Oregon, for a local tsunami generated by a Cascadia subduction zone earthquake. We establish evacuation paths by calculating the least-cost distance (LCD) to safety for every grid cell in a tsunami hazard zone using geospatial, anisotropic path distance algorithms. Minimum BTW speed to safety on LCD paths is calculated for every grid cell by dividing surface distance from that cell to safety by the tsunami arrival time at safety. We evaluated three scenarios of evacuation difficulty: (1) all bridges are intact with a 5-min evacuation delay from the start of earthquake, (2) only retrofitted bridges are considered intact with a 5-min delay, and (3) only retrofitted bridges are considered intact with a 10-min delay. BTW maps also take into account critical evacuation points along complex shorelines (e.g., peninsulas, bridges over shore-parallel estuaries) where evacuees could be caught by tsunami waves. The BTW map is able to communicate multiple pedestrian travel speeds, which are typically visualized by multiple maps with current LCD-based mapping practices. Results demonstrate that evacuation of Seaside is problematic seaward of the shore-parallel waterways for those with any limitations on mobility. Tsunami vertical evacuation refuges or additional pedestrian bridges may be effective ways of reducing loss of life seaward of these waterways.
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