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Evaluation of Contamination and Remediation Manvel Saltwater Disposal Site Brazoria County, Texas
The Manvel Saltwater Disposal (SWD) site (RRC Site No. 92-03-00003), which lies within the city limits of Manvel, Texas, in Brazoria County, was investigated by the Bureau of Economic Geology during a 5-month study from July through November 2015. The study included hydrogeological investigation, waste characterization, assessment of environmental impact, and evaluation of remediation options.
Saltwater, drilling waste, and crude oil have been disposed of at the site. There have been several instances of pit overflow, levee rupture, or both, resulting in contamination of the surrounding area by saltwater and crude oil. There have been several public complaints to regulatory agencies, centered on the perceived threat to groundwater quality. The site lies in the outcrop of the Beaumont Formation, where the formation is sufficiently thick to be a local aquifer, containing freshwater with chlorinities of less than 100 mg/L. The Beaumont lies above and is hydrologically distinct from the main water-yielding part of the Chicot aquifer.Bureau of Economic Geolog
Galaxy Peculiar Velocities From Large-Scale Supernova Surveys as a Dark Energy Probe
Upcoming imaging surveys such as the Large Synoptic Survey Telescope will
repeatedly scan large areas of sky and have the potential to yield
million-supernova catalogs. Type Ia supernovae are excellent standard candles
and will provide distance measures that suffice to detect mean pairwise
velocities of their host galaxies. We show that when combining these distance
measures with photometric redshifts for either the supernovae or their host
galaxies, the mean pairwise velocities of the host galaxies will provide a dark
energy probe which is competitive with other widely discussed methods. Adding
information from this test to type Ia supernova photometric luminosity
distances from the same experiment, plus the cosmic microwave background power
spectrum from the Planck satellite, improves the Dark Energy Task Force Figure
of Merit by a factor of 1.8. Pairwise velocity measurements require no
additional observational effort beyond that required to perform the traditional
supernova luminosity distance test, but may provide complementary constraints
on dark energy parameters and the nature of gravity. Incorporating additional
spectroscopic redshift follow-up observations could provide important dark
energy constraints from pairwise velocities alone. Mean pairwise velocities are
much less sensitive to systematic redshift errors than the luminosity distance
test or weak lensing techniques, and also are only mildly affected by
systematic evolution of supernova luminosity.Comment: 18 pages; 4 figures; 4 tables; replaced to match the accepted versio
Supervoid Origin of the Cold Spot in the Cosmic Microwave Background
We use a WISE-2MASS-Pan-STARRS1 galaxy catalog to search for a supervoid in
the direction of the Cosmic Microwave Background Cold Spot. We obtain
photometric redshifts using our multicolor data set to create a tomographic map
of the galaxy distribution. The radial density profile centred on the Cold Spot
shows a large low density region, extending over 10's of degrees. Motivated by
previous Cosmic Microwave Background results, we test for underdensities within
two angular radii, , and . Our data, combined with an
earlier measurement by Granett et al 2010, are consistent with a large supervoid with centered at . Such a supervoid, constituting a
fluctuation in the model, is a plausible cause
for the Cold Spot.Comment: 4 pages, 2 figures, Proceedings of IAU 306 Symposium: Statistical
Challenges in 21st Century Cosmolog
Science Objectives and Early Results of the DEEP2 Redshift Survey
The DEIMOS spectrograph has now been installed on the Keck-II telescope and
commissioning is nearly complete. The DEEP2 Redshift Survey, which will take
approximately 120 nights at the Keck Observatory over a three year period and
has been designed to utilize the power of DEIMOS, began in the summer of 2002.
The multiplexing power and high efficiency of DEIMOS enables us to target 1000
faint galaxies per clear night. Our goal is to gather high-quality spectra of
\~60,000 galaxies with z>0.75 in order to study the properties and large scale
clustering of galaxies at z ~ 1. The survey will be executed at high spectral
resolution, , allowing us to work
between the bright OH sky emission lines and to infer linewidths for many of
the target galaxies (for several thousand objects, we will obtain rotation
curves as well). The linewidth data will facilitate the execution of the
classical redshift-volume cosmological test, which can provide a precision
measurement of the equation of state of the Universe. This talk reviews the
project, summarizes our science goals and presents some early DEIMOS data.Comment: 12 pages, 5 figures, talk presented at SPIE conference, Aug. 200
The DEEP2 Galaxy Redshift Survey: The Evolution of Void Statistics from z~1 to z~0
We present measurements of the void probability function (VPF) at z~1 using
data from the DEEP2 Redshift Survey and its evolution to z~0 using data from
the Sloan Digital Sky Survey (SDSS). We measure the VPF as a function of galaxy
color and luminosity in both surveys and find that it mimics trends displayed
in the two-point correlation function, ; namely that samples of brighter,
red galaxies have larger voids (i.e. are more strongly clustered) than fainter,
blue galaxies. We also clearly detect evolution in the VPF with cosmic time,
with voids being larger in comoving units at z~0. We find that the reduced VPF
matches the predictions of a `negative binomial' model for galaxies of all
colors, luminosities, and redshifts studied. This model lacks a physical
motivation, but produces a simple analytic prediction for sources of any number
density and integrated two-point correlation function, \bar{\xi}. This implies
that differences in the VPF across different galaxy populations are consistent
with being due entirely to differences in the population number density and
\bar{\xi}. The robust result that all galaxy populations follow the negative
binomial model appears to be due to primarily to the clustering of dark matter
halos. The reduced VPF is insensitive to changes in the parameters of the halo
occupation distribution, in the sense that halo models with the same \bar{\xi}
will produce the same VPF. For the wide range of galaxies studied, the VPF
therefore does not appear to provide useful constraints on galaxy evolution
models that cannot be gleaned from studies of \bar{\xi} alone. (abridged)Comment: 17 pages, 15 figures, ApJ accepte
Maximum-Likelihood Comparisons of Tully-Fisher and Redshift Data. II. Results from an Expanded Sample
This is the second in a series of papers in which we compare Tully-Fisher
(TF) data from the Mark III Catalog with predicted peculiar velocities based on
the IRAS galaxy redshift survey and gravitational instability theory, using a
rigorous maximum likelihood method called VELMOD. In Paper I (Willick et al.
1997b), we we applied the method to a km/sec, 838-galaxy TF
sample and found where
and is the linear biasing parameter for IRAS galaxies. In this paper we
increase the redshift limit to km/sec, thereby enlarging the
sample to 1876 galaxies. The expanded sample now includes the W91PP and CF
subsamples of the Mark III catalog, in addition to the A82 and MAT subsamples
already considered in Paper I.
We implement VELMOD using both the forward and inverse forms of the TF
relation, and allow for a more general form of the quadrupole velocity residual
detected in Paper I. We find (1-sigma error) at 300
km/sec smoothing of the IRAS-predicted velocity field. The fit residuals are
spatially incoherent for indicating that the IRAS plus
quadrupole velocity field is a good fit to the TF data. If we eliminate the
quadrupole we obtain a worse fit, but a similar value for of Changing the IRAS smoothing scale to 500 km/sec has almost no effect on
the best We find evidence for a density-dependence of the
small-scale velocity dispersion,
km/sec.Comment: Latex, 37 pages, 15 figures, uses modified apjpt4.st
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