VARIATIONS OF SOIL-BEDROCK GEOCHEMISTRY ALONG A SAN GABRIEL VALLEY CATENA: IMPLICATIONS FOR LANDSCAPE EVOLUTION IN A CHANGING SOUTHERN CALIFORNIA XERIC CLIMATE

2020 ◽  
Author(s):  
Jennifer Bass ◽  
◽  
Colin Robins
Keyword(s):  
Southern California ◽  
Landscape Evolution ◽  
San Gabriel Valley

WHAT DO WE KNOW ABOUT LATE CENOZOIC LANDSCAPE EVOLUTION AT THE NORTHWEST HEAD OF THE SALTON TROUGH, SOUTHERN CALIFORNIA?

2016 ◽  
Author(s):  
Jonathan C. Matti ◽  
◽  
Katherine J. Kendrick ◽  
Robert E. Powell ◽  
Shannon A. Mahan ◽  
...  
Keyword(s):  
Southern California ◽  
Landscape Evolution ◽  
Late Cenozoic ◽  
Salton Trough

Tectonically-dominated Quaternary landscape evolution of the Ventura basin, southern California, quantified using cosmogenic isotopes and topographic analyses

2020 ◽  
Author(s):  
Dylan Rood ◽  
Alex Hughes ◽  
Alex Whittaker ◽  
Rebecca Bell ◽  
Klaus Wilcken ◽  
...  
Keyword(s):  
Southern California ◽  
Landscape Evolution ◽  
Sedimentary Basins ◽  
Temporal Variations ◽  
Channel Morphology ◽  
Primary Control ◽  
Fault Activity ◽  
Erosion Rates ◽  
Ventura Basin ◽  
Channel Steepness

<p>Spatial and temporal variations in fault activity informs models of seismic hazards and can affect local patterns of relief generation and channel morphology. Therefore, the quantification of rates of fault activity has important applications for understanding natural hazards and landscape evolution. Here, we quantify the complex interplay among tectonic uplift, topographic development, and channel erosion recorded in the hanging walls of several seismically-active reverse faults in the Ventura basin, southern California, USA. We use cosmogenic <sup>26</sup>Al/<sup>10</sup>Be isochron burial dating to construct a basin-wide geochronology for the Saugus Formation: an important, but poorly dated, regional Quaternary strain marker. Our geochronology of the Saugus Formation is used to calculate tectonically-driven rock uplift rates and reduce uncertainties in fault-slip rates. In addition, we calculate <sup>10</sup>Be catchment-averaged erosion rates, characterise patterns of catchment relief and channel steepness indices, and analyse river long-profiles in fault hanging walls to compare with patterns of fault displacement rates averaged over various temporal scales.</p><p> </p><p>The results of the burial dating confirm that the Saugus Formation is time-transgressive with ages for the top of the exposed Saugus Formation of ~0.4 Ma in the western Ventura basin and ~2.5 Ma in the eastern Ventura basin. The burial ages for the base of shallow marine sands, which underlie the Saugus Formation throughout the basin, are ~0.6 Ma in the western Ventura basin and ~3.3 Ma in the eastern Ventura basin. The results of the landscape analysis indicate that relief, channel steepness, and erosion rates are still adjusting to tectonic boundary conditions imposed by different tectonic perturbations that have occurred at various times since ~1.5 Ma, which include fault initiation and fault linkage. The data presented here suggest that, for transient landscapes in sedimentary basins up to 2500 km<sup>2</sup>, where climate can be considered uniform, fault activity is the primary control on patterns of relief generation and channel morphology over periods of 10<sup>4 </sup>to 10<sup>6 </sup>years.</p>

Planning Truck-Only Lanes: Emerging Lessons from the Southern California Experience

2003 ◽  
Vol 1833 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Michael J. Fischer ◽  
Dike N. Ahanotu ◽  
Janine M. Waliszewski
Keyword(s):  
United States ◽  
Los Angeles ◽  
Southern California ◽  
The United States ◽  
Time Of Day ◽  
Inland Empire ◽  
Capital Costs ◽  
San Gabriel Valley ◽  
History Of ◽  
Analytical Tools

Recent efforts to develop truck-only facilities in the United States are discussed. The rationale for truck-only highways is described, and the history of efforts to separate trucks and automobiles on the nation's roadways is presented. The truck lane program of the Southern California Association of Governments is one of the most ambitious programs of its type in the United States. Preliminary analysis of truck lanes for SR-60 and I-710 is described. SR-60 is an east–west corridor linking downtown Los Angeles with the warehouse and manufacturing districts of the San Gabriel Valley and the Inland Empire. 1-710 is the major access route to the ports of Los Angeles and Long Beach. Both freeways each have one of the highest truck volumes in California, and truck mobility on these corridors is a significant problem. Truck lane projects on SR-60 and I-710 are in the feasibility analysis stage and much has been learned in these early studies. Various issues are addressed, including the trade-off between limiting access to improve operational costs and limit capital costs, need to generate demand, time-of-day distribution of truck traffic and its relationship to potentially benefit truck mobility, and need for improved analytical tools. Also described are issues related to facility design and configuration, demand analysis, and toll analysis.

The Effects of Presentation on Noise and Dental Appliances on Speech

1981 ◽  
Vol 24 (1) ◽  
pp. 151-151
Author(s):  
Lillian Glass ◽  
Sharon R. Garber ◽  
T. Michael Speidel ◽  
Gerald M. Siegel ◽  
Edward Miller
Keyword(s):  
Southern California ◽  
University Of Southern California ◽  
University Of Minnesota ◽  
School Of Medicine ◽  
Southern California School ◽  
School Of Dentistry ◽  
The University

An omission in the Table of Contents, December JSHR, has occurred. Lillian Glass, Ph.D., at the University of Southern California School of Medicine and School of Dentistry, was a co-author of the article "The Effects of Presentation on Noise and Dental Appliances on Speech" along with Sharon R. Garber, T. Michael Speidel, Gerald M. Siegel, and Edward Miller of the University of Minnesota, Minneapolis.

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