Computer simulation of shelf and stream profile geomorphic evolution resulting from eustasy and uplift
Abstract
A two-dimensional computer simulation of shelf and stream profile evolution with sea level oscillation has been developed to illustrate the interplay of coastal and fluvial processes on uplifting continental margins. The shelf evolution portion of the simulation is based on the erosional model of Trenhaile (1989). The rate of high tide cliff erosion decreases as abrasion platform gradient decreases the sea cliff height increases. The rate of subtidal erosion decreases as the subtidal sea floor gradient decreases. Values are specified for annual wave energy, energy required to erode a cliff notch 1 meter deep, nominal low tidal erosion rate, and rate of removal of cliff debris. The values were chosen arbitrarily to yield a geomorphic evolution consistent with the present coast of northern California, where flights of uplifted marine terraces are common. The stream profile evolution simulation interfaces in real time with the shelf simulation. The stream profile consists of uniformly spaced cells, each representing the median height of a profile segment. The stream simulation results show that stream response to sea level change on an uplifting coast is dependent on the profile gradient near the stream mouth, relative to the shelf gradient. Small streams with steep gradients aggrade ontomore »
- Authors:
-
- Forest Service, Placerville, CA (United States)
- Publication Date:
- OSTI Identifier:
- 5020994
- Report Number(s):
- CONF-9305259-
Journal ID: ISSN 0016-7592; CODEN: GAAPBC
- Resource Type:
- Conference
- Journal Name:
- Geological Society of America, Abstracts with Programs; (United States)
- Additional Journal Information:
- Journal Volume: 25:5; Conference: 89. annual meeting of the Cordilleran Section and the 46th annual meeting of the Rocky Mountain Section of the Geological Society of America (GSA), Reno, NV (United States), 19-21 May 1993; Journal ID: ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 58 GEOSCIENCES; 54 ENVIRONMENTAL SCIENCES; CALIFORNIA; COASTAL REGIONS; EROSION; GEOMORPHOLOGY; ALLUVIAL DEPOSITS; COMPUTERIZED SIMULATION; CONTINENTAL SHELF; GEOLOGIC MODELS; SEA LEVEL; SHORES; STREAMS; TWO-DIMENSIONAL CALCULATIONS; WATER WAVES; WAVE FORCES; CONTINENTAL MARGIN; DEVELOPED COUNTRIES; GEOLOGIC DEPOSITS; GEOLOGY; GRAVITY WAVES; LEVELS; NORTH AMERICA; SIMULATION; SURFACE WATERS; USA; 580000* - Geosciences; 540250 - Environment, Terrestrial- Site Resource & Use Studies- (1990-)
Citation Formats
Johnson, R M. Computer simulation of shelf and stream profile geomorphic evolution resulting from eustasy and uplift. United States: N. p., 1993.
Web.
Johnson, R M. Computer simulation of shelf and stream profile geomorphic evolution resulting from eustasy and uplift. United States.
Johnson, R M. 1993.
"Computer simulation of shelf and stream profile geomorphic evolution resulting from eustasy and uplift". United States.
@article{osti_5020994,
title = {Computer simulation of shelf and stream profile geomorphic evolution resulting from eustasy and uplift},
author = {Johnson, R M},
abstractNote = {A two-dimensional computer simulation of shelf and stream profile evolution with sea level oscillation has been developed to illustrate the interplay of coastal and fluvial processes on uplifting continental margins. The shelf evolution portion of the simulation is based on the erosional model of Trenhaile (1989). The rate of high tide cliff erosion decreases as abrasion platform gradient decreases the sea cliff height increases. The rate of subtidal erosion decreases as the subtidal sea floor gradient decreases. Values are specified for annual wave energy, energy required to erode a cliff notch 1 meter deep, nominal low tidal erosion rate, and rate of removal of cliff debris. The values were chosen arbitrarily to yield a geomorphic evolution consistent with the present coast of northern California, where flights of uplifted marine terraces are common. The stream profile evolution simulation interfaces in real time with the shelf simulation. The stream profile consists of uniformly spaced cells, each representing the median height of a profile segment. The stream simulation results show that stream response to sea level change on an uplifting coast is dependent on the profile gradient near the stream mouth, relative to the shelf gradient. Small streams with steep gradients aggrade onto the emergent shelf during sea level fall and incise at the mountain front during sea level rise. Large streams with low gradients incise the emergent shelf during sea level fall and aggrade in their valleys during sea level rise.},
doi = {},
url = {https://www.osti.gov/biblio/5020994},
journal = {Geological Society of America, Abstracts with Programs; (United States)},
issn = {0016-7592},
number = ,
volume = 25:5,
place = {United States},
year = {Thu Apr 01 00:00:00 EST 1993},
month = {Thu Apr 01 00:00:00 EST 1993}
}