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C. E. Jacob

Publications and source records attributed to C. E. Jacob.

12 recordsLinked to original sources
USGS2014

Fluctuations in artesian pressure produced by passing railroad‐trains as shown in a well on Long Island, New York

Perhaps one of the chief interests of ground‐water hydrologists is the study of water‐level fluctuations. Since the beginning of the science of hydrology attempts have been made to interpret these phenomena and determine their significance. On the basis of actual observations and “with special reference to Long Island, New York,” Veatch [see 1 of “References” at end of paper] in 1906 considered in some detail several different causes of water‐level fluctuations. He placed the known causes under two general headings, natural and human. However, considering proximate rather than ultimate causes a further classification might be, and indeed often is, made with regard to the conditions under which the fluctuations are produced by a given agency, natural or human. Thus we speak of ”water‐table conditions“ and ”artesian conditions,“ realizing, however, that the distinction between the two is not always definite. The phenomena peculiar to artesian conditions are usually the result merely of the imperviousness of the confining beds relative to the particular aquifer under consideration. Indeed, it is recognized that perhaps even the most dense clay is not absolutely impervious to the flow of water, given a difference in head, sufficient to produce the flow, though it may be beyond the precision of the means now employed to detect the flow of water through such impervious strata.

New York↗
USGS2014

On the flow of water in an elastic artesian aquifer

Slichter showed in 1898 that a solution may be obtained for a given problem in the steady motion of ground‐water by solving the familiar Laplace equation and that therefore in steady‐state conditions a problem in the motion of ground‐water is mathematically analogous to a problem in the steady flow of heat or electricity [see 1 of “References” at end of paper]. More recently it has been recognized that the analogy holds also for the non‐steady‐state flow of compressible liquids, in elastic systems as well as in rigid systems. In studying the effect of the discharge of flowing wells on the head in the Dakota sandstone, Meinzer [2, 3] concluded that the water discharged by the wells had largely been derived locally from storage. It was found that the amount of water withdrawn from storage could not be accounted for on the basis of the compressibility of water alone but that it might be accounted for on the basis of the probable compressibility of the sandstone itself. Prior to that time, estimates of water‐supplies from artesian aquifers had been based upon the assumption that artesian aquifers are perfectly incompressible and inelastic However, as Meinzer states [2, p. 289], “artesian aquifers are apparently all more or less compressible and elastic though they differ widely in the degree and relative importance of these properties. In general, the properties of compressibility and elasticity are of the most consequence in aquifers that have low permeability, slow recharge, and high head.”

Eos, Transactions, American Geophysical Union↗
USGS2014

Coefficients of storage and transmissibility obtained from pumping tests in the Houston District, Texas

An investigation of the ground‐water supply of the Houston District, in Texas, has been in progress since December, 1930, under the general direction of O. E. Meinzer, Geologist‐in‐Charge of the Division of Ground Water of the Geological Survey. The Houston District, as the term is used here, comprises all of Harris County and parts of Montgomery, Waller, and Fort Bend counties, lying between the Trinity and Brazos rivers. The investigation in this area has consisted primarily of inventorying well‐logs and pumpage‐records, of obtaining water‐level data and information regarding the chemical character of the ground‐water, and wherever possible of correlating these data.

Texas↗
USGS2014

Notes on the elasticity of the Lloyd sand on Long Island, New York

The Lloyd sand is a productive artesian aquifer underlying all of Long Island except the westernmost part. It rests unconformably upon a floor of crystalline rock that slopes toward the southeast at about 100 feet to the mile. Locally the bed‐rock surface has a relief of more than 100 feet. The Lloyd sand consists of white quartz‐sand and gravel, with some layers of clay. It is considered to be part of the Raritan—the basal formation of the Upper Cretaceous series. At Rockaway Park, on the south shore of the Island, the Lloyd is about 200 feet thick and is overlain by 300 feet of clays of Raritan age. The Raritan clays are in turn overlain by about 150 feet of sands, believed to be of Magothy age, and about 315 feet of Pleistocene sediments.

New York↗
USGS2014

Correlation of ground‐water levels and precipitation on Long Island, New York

Long Island simulates in a general way an aquifer in the form of an infinite strip confined between parallel boundaries at constant head (sea‐level), over which recharge precipitation is assumedly uniform. The non‐steady flow of water in this idealized system is analyzed assuming provisionally that the effective thickness of saturated beds below sea‐level is great compared to the maximum height of the water‐table above sea‐level. The rate of accretion to the water‐table is assumed to vary discontinuously, supposedly being constant for each of the successive periods (yearly or monthly) and proportional to the average rate of precipitation during that period. The decay of the water‐table profile, beginning with any one of the succession of super‐posed non‐steady states, is shown to follow in general a relation composed of terms varying with time as exp(−t/t o ) in which t o is a function of the effective porosity, the thickness and the transmission‐constant of the aquifer. This exponential curve may be approximated by a parabola which is used to determine values of “effective average rate of precipitation” from published records in annual or monthly precipitation. By the “effective average rate of precipitation” at any time is meant that rate of precipitation which, had it been maintained uninterruptedly throughout the past, would have produced the same water‐table profile as actually existed at that particular time. It is demonstrated that fee effective average rate of precipitation may be determined also simply by cumulating departures from progressive averages of precipitation, multiplying the values thus determined by a known rational coefficient, and adding the appropriate initial value of effective average precipitation.

New York↗
USGS2014

Correlation of ground‐water levels and precipitation on Long Island, New York

A brief though concise statement of the history of ground‐water studies on Long Island, beginning with the early water‐level observations in Brooklyn by STODDARD in 1854, was given by THOMPSON [see 7 of “References” at end of paper]. These and other early data were considered later by LEGGETTE [8]. He evaluated them by means of a graph of the cumulative departure of precipitation. More recent studies by LEGGETTE [9] and by the writer have lead to the procedure outlined in Part I of this paper [10], which was founded upon an empirical approach suggested by LEGGETTE and was later justified by analysis based on the theory of BOUSSINESQ [11].

New York↗
USGS2014

Radial flow in a leaky artesian aquifer

A partial differential equation is set up for radial flow in an elastic artesian aquifer into which there is vertical leakage in proportion to the drawdown. This differential equation is integrated to obtain two steady state solutions, one for the case of a well in an infinite aquifer, and the other for the case where the head is maintained constant along an outer boundary concentric with the well. In the second case, the solution of the non‐steady state is also obtained for flow towards a well discharging at a steady rate, the initial state being one of uniform head distribution. A table and some curves are given for one set of assumed values of three of the parameters of the system.

Eos, Transactions, American Geophysical Union↗
USGS2014

Appendix A—Report of the subcommittee on permeability

The Subcommittee on Permeability of the Permanent Research Committee on Ground Water of the Section of Hydrology, was organized in 1943 to provide for the open discussion of the terminology relating to permeability with a view toward the elimination of conflicting usages and the clarification and standardization of acceptable terms. Confusion had arisen not only in the units of measurement but also in the notation and nomenclature of permeability. It seemed desirable to have general agreement particularly in regard to the names of the different physical parameters in common use and their symbols.

Eos, Transactions, American Geophysical Union↗
USGS2014

Appendix D—Notes on Darcy's law and permeability

In any effort to establish nomenclature relating to the flow of fluids through porous media it would seem well first to consider the history of the development of our concepts and of the terms or expressions involved. Only in this way can precedent rightfully be honored and at the same time duplicating expressions be eliminated and the remaining more useful terms clarified. Then, proceeding with a foresight lined up with recent advances, we may hope to anticipate the needs of the future.

Eos, Transactions, American Geophysical Union↗
USGS2014

A generalized graphical method for evaluating formation constants and summarizing well‐field history

The capacities of a water‐bearing formation to transmit water under a hydraulic gradient and to yield water from storage when the water table or artesian pressure declines, are generally expressed, respectively, in terms of a coefficient of transmissibility and a coefficient of storage. Determinations of these two constants are almost always involved in quantitative studies of ground‐water problems.

Eos, Transactions, American Geophysical Union↗