The Salton Sea, situated in the Lower Colorado River Basin (LCRB), is under duress due to, among other things, increased water demands of cities like San Diego, California and Mexicali, Mexico. This research developed a tool to investigate the implications of water transfers on the health and sustainability of the Salton Sea Ecosystem. The Salton Sea model is a spatially-explicit, stochastic, simulation model representing water flow, i.e., water volume and quantity of Total Dissolved Salts (TDS) and Phosphorus (P), in the LCRB as it enters the Salton Sea. The model is formulated as a compartment model based on difference equations with a daily time step using STELLA® 8.0 software. The model was developed, evaluated, and applied to simulate the potential effects on the population dynamics of selected fish and avian species at the Salton Sea under six different scenarios. Oneway ANOVAs and Bonferroni Multiple Comparison Post Hoc Tests were performed for the water management scenarios and selected variables involving the fish and bird population dynamics using SPSS version 12.0.1 (SPSS Inc., 2003). Weather station daily data were collected for both precipitation and Eto for a 25- year period (1980-2004) for the Salton Sea area. Thirty-four probability distributions were fit to the monthly datasets. Monthly distributions were used to preserve seasonality when modeling future climate scenarios. Additionally, binomial and multinomial logistic regression models were utilized to determine the relationships concerning precipitation events and Eto levels. Further, two strategies were employed in modeling the uncertainty in future climate patterns, namely deterministic and stochastic versions of the driving variables. A climate sensitivity analysis was also conducted and results showed that the cumulative effects and change of plus or minus 10 percent in Salton Sea inflows can have significant effects on sea elevation and salinity. Both of the Salton Sea impoundment scenarios significantly (P<0.05) lowered the salinity in the north or main sea impoundments compared to future downward trends in sea elevation and upward trends in salinity under baseline conditions. Further, the elevations of the north or main sea impoundments were stabilized at -220 by the end of 2024. Should action be taken to stabilize the sea and reduce salinity, the impoundment scenarios demonstrated the most success in the present study. If no such action is taken, the simulation results demonstrate that the current community dynamics of the Salton Sea will be further impaired as a result.

Thesis (Ph. D.)--University of Chicago, 1912. / Plate 13-14 each preceded by leaf with descriptive letter press. [Reprinted from Publication 193 of the Carnegie institution of Washington].

Thesis (M.S.)--San Diego State University, 1994. / Includes bibliographical references (leaves 69-75).

Thesis (Ph. D.)--University of Chicago, 1912. / Plate 13-14 each preceded by leaf with descriptive letter press. [Reprinted from Publication 193 of the Carnegie institution of Washington]. Also available on the Internet. Also issued online.

The southern - 100 km long Coachella section of the San Andreas fault is the only section of the fault in southern California that has not experienced a historical earthquake, and it may be the most overdue section of the fault. Numerical models of rupture propagation shows that a large earthquake with a nucleation one in the Durmid Hill field area would produce particularly destructive and deadly ground shaking in southern California. This is used as the model earthquake for the ShakeOut exercises in southern California because it is may represent the worst-case scenario for southern California but does not appear to be a very likely scenario following this research. Building on existing geologic mapping that shows major Pleistocene to Holocene contraction near the hypothesized nucleation, we use geologic mapping to develop and validate a competing geometric and kinematic model for the southern tip of the San Andreas Fault. A ladder-like-fault model explains the widespread contraction in the Durmid Hill study area as the result of contraction between the main strand of the San Andreas fault and East Shoreline strand. The East Shoreline strand of the San Andreas fault is the newly discovered fault and is dispersed across a zone between 0.5 to 1 km wide, and encompasses an area on the northeast shore of the Salton Sea. There is persistent and strong contraction across the entire - 1.5 to 3.5 km wide San Andreas fault zone because both dextral "side-rail" faults are counterclockwise, and in a contractional bend, relative to current plate motions. This contractional bend was previously documented for the main strand of San Andreas fault. A new digital geologic map and field studies document the stratigraphy and structures at a range of scales between Bombay Beach and Salt Creek. Numerous folds, narrow strike-slip and oblique-slip faults, and sheared damaged rocks in latest Miocene (?) to Holocene sediment lie within the wide and very complex damage zone of the main strand of the San Andreas fault zone. The East Shoreline strand of the San Andreas fault system buffers the main strand from major stress changes produced by deformation along the sinistral to sinistral-normal Extra fault array under the Salton Sea.

This research attempted to uncover the sociopolitical ideologies, ethnic discrimination, and class oppression that create sustained social dominance through resource control in the unicorporated community of the Salton Sea located in Eastern Riverside County, California in regard to public transportation issues.

In the middle of the California Desert is an inland desert sea, called the Salton Sea. Its existence is curious, nearly magical. It is California’s largest lake, it is saltier than the Pacific Ocean, it is slowly dying, and its existence is a complete accident. This thesis breaks down the historical narrative of the Salton Sea from a white settler perspective, using theories posed by Yi Fu Tuan about distinctions between space and place. The temporality of spatial locations, the construction of the binaries natural/built, and the moralizing of landscapes all provide further understanding of the Salton Sea’s existence. Throughout history, the white settlers of the Imperial Desert have projected, their morals and desires upon the desert landscape, reforming the space into their vision of the future as a result of their abilities to tame and control rivers. Instead of a future, they produced a place replete with the past: a place considered worthless and potentially dangerous. Through looking at the constructions of space, place, memory, and history, we are better able to understand the birth of this desert sea.

Prehistoric life in the Colorado Desert endured a variety of environmental extremes. Episodic flooding and shifts in the course of the Colorado River resulted in the infilling of the Salton Basin and created a large freshwater lake known as Lake Cahuilla. Settlement along the different segments of the lakeshore is considered variable and may reflect accessibility to nearby viable resources. Remains from archaeological excavations at lakeshore sites show that lacustrine resources and fishing opportunities attracted prehistoric groups to the ancient lake. How prehistoric groups organized themselves and utilized lakeshore and nearby resources offer opportunities to explore the subsistence and mobility strategies of populations living in an oscillating environmental context. Using information generated from past Cultural Resource Management projects, the current study analyzes multiple data sets to address questions of a regional scale to more fully understand the effects of cyclical Lake Cahuilla on desert inhabitants. Analysis of existing collections and their associated documentation from late prehistoric habitation sites adjacent to the northwestern maximum shoreline as well as recessional shoreline sites some 30 miles to the south provide additional information on resource availability in a changing environment. It appears that in some circumstances the northwestern lakeshore inhabitants adapted to a changing environment and maintained occupation spanning multiple lake stands. During high stands, subsistence practices focused on lacustrine resources until no longer viable and habitation sites feature specialized subsistence technology reflecting fish procurement and processing. During lake recession, at least short-term habitation was sustained and corresponded to the exploitation of specific fish and waterfowl species. This study will help us better understand the strategies employed by groups who utilized the resources of this fluctuating lacustrine environment. Examination of resource use and mobility patterns practiced by prehistoric Lake Cahuilla inhabitants allows for interpretations of the adaptations necessary for life within this desert region. Ultimately, this research is applicable to broader anthropological queries on a regional scale. The Salton Basin is positioned within a geographical region that likely experienced influence and change from the surrounding environs. Gaining a deeper understanding of the study area will ultimately aid in future research concerning environmental adaptation, exchange relations, and culture change among the neighboring regions of the Mojave and Great Basin deserts, the agricultural Southwest, adjacent mountains and coast lines, and Baja California (Schaefer and Laylander 2007:381). Additionally, an understanding of how resource availability influenced past populations can contribute to ongoing and future studies concerned with resource management in the Colorado Desert and similar xeric environments.

The Fish Creek-Vallecito section is the most stratigraphically complete and structurally intact Neogene exposure in the Salton Trough, and thus provides a useful reference section for regional stratigraphie revision and historical interpretation of the early Gulf of California and Colorado Delta. The section comprises a marine sequence (Imperial Formation) bracketed by nonmarine units (Split Mountain and Alverson Formations below, Palm Spring Formation and Canebrake Conglomerate above). Recognition of distinct suites of locally-derived and Colorado River-derived sediment, combined with sedimentological evidence, led to revision of this sequence in terms of informal members and geneticstratigraphic units: (1) pre-rift braided-stream deposits (2) syn-rift fanglomerates and volcanics, with local pre-marine evaporites; (3) pre-deltaic marine units, deposited primarily as small fan deltas; a progradational sequence of the ancestral Colorado delta, consisting of (4) an upward-shoaling marine sequence, and (5) a nonmarine deltaplain sequence; (6) lacustrine units; and (7) locally-derived basinmargin alluvium that interfingers with (4), (5) and (6). Neogene palinspastic base maps for paleogeographic mapping were based on displacement histories for the Pacific-North American plate boundary and its constituent faults. The tectonic-sedimentary history consists of: (1) early to middle Miocene rifting that propagated southward from southern California to the Gulf mouth; (2) northward marine transgression of the rift basin, reaching southern California by the late Miocene; (3) development of the San Andreas-Gulf of California transform boundary by inboard transfer of intraplate slip; (4) earliest Pliocene initiation of the lower Colorado River and Delta by rapid epeirogenic uplift of the Bouse Embayment; and (5) late Pliocene or Pleistocene transpressive uplift in the western Salton Trough caused by outboard transfer of slip from the San Andreas fault. The stratigraphic succession in the western Salton Trough resulted largely from tectonic transport through a series of paleoenvironments anchored to the North American plate by the entry point of the Colorado River.

Using Coachella Valley's Salton Sea ecosystem as a model, several multidisciplinary wetland activities for grades three to six were developed. A resource guide for educators is included.