Pleistocene cataclysmic flooding along the Big Lost River, east central Idaho

نویسنده

  • Sara L. Rathburn
چکیده

Relationships between cataclysmic flood-generated landforms and flood hydraulics were investigated along Box Canyon, an 11 km long bedrock gorge of the lower Big Lost River. Geomorphic mapping along Box Canyon indicates that a cataclysmic flood completely inundated the gorge, resulting in large-scale erosional and depositional features on the adjacent basalt upland. Step-backwater hydraulic modeling indicates that a discharge of 60,000 m 3 s~ was required to produce the geologic paleostage evidence. Maximum stream power per unit area of bed locally attained values of 26,000 W m-2 during the peak, ranking the Big Lost River flood third, in terms of power, behind the famous Missoula and Bonneville floods. The spatial distribution of unit stream power indicates that bedrock erosion and boulder deposition on the basalt upland adjacent to Box Canyon were governed primarily by decreasing unit stream power and/or fluctuating unit stream power gradients. A preliminary depositional threshold for the largest flood boulders defines a lower limit of flood power required to sustain boulder transport along this bedrock fluvial system. Ultimately, hydrodynamic controls on Box Canyon flood erosion and deposition derive from the irregular volcanic rift topography of the eastern Snake River Plain. Outburst floods from a glacial lake in headwater regions during the late Pleistocene may have induced the torrential discharges within Box Canyon.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Un Co Rr Ec Te D Pr Oo F 1 Physical and Economic Sustainability of Water : New 2 Approach Using the Case of the Big Lost River , Idaho 3

3 AHMED SAID*, DAVID K. STEVENS and GERALD SEHLKE 4 Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL, USA; 5 2 Civil and Environmental Engineering Department, Utah State University, Logan, UT, USA; 6 3 Integrated Environmental Analysis Department, Idaho National Engineering and Environmental 7 Laboratory, Idaho Falls, Idaho, USA 8 (*author for correspond...

متن کامل

The benefits of basing policies on the 20-year GWP of HFCs

The steady growth in extreme weather events around the world signals that human-induced climate change is happening right now. In 2010 and 2011 we have witnessed unparalleled devastation around the world from record floods, fires, droughts, more frequent and intense tornadoes and hurricanes. In some countries, millions of acres of agricultural land have been lost due to flooding, while other co...

متن کامل

Analysis of Pleistocene paleodrainage evolution in the Po Basin (Italy) by multivariate statistical techniques

In order to obtain a high-resolution Pleistocene stratigraphy, eleven continuously cored boreholes, 100 to 220m deep were drilled in the northern part of the Po Plain by Regione Lombardia in the last five years. Quantitative provenance analysis (QPA, Weltje and von Eynatten, 2004) of Pleistocene sands was carried out by using multivariate statistical analysis (principal component analysis, PCA,...

متن کامل

Structural Model for the Columbia River Basalt Near Riggins, Idaho by

Imnaha Basalt and Grande Ronde Basalt (RI) of the Columbia River Basalt Group form a small synclinal basin immediately west of Riggins, Idaho. The displacement of the margins of the basalt outcrop, of the synclinal axis, and of a dike of Saddle Mountains(?) Basalt define a pattern best explained by a model of west-northwest to eastsoutheast and north-northwest to south-southeast dextral strike-...

متن کامل

Ecophysiology of riparian cottonwoods: stream flow dependency, water relations and restoration.

Cottonwoods (Populus spp.) are adapted to riparian or floodplain zones throughout the Northern Hemisphere; they are also used as parents for fast-growing hybrid poplars. We review recent ecophysiological studies of the native cottonwoods Populus angustifolia James, P. balsamifera L., P. deltoides Marsh., P. fremontii S. Watson and P. trichocarpa T. & G. in North America, and P. nigra L. in Euro...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2002