Applications of Elastic Modeling, Thermobarometry, and Thermal History Modeling to (Ultra)high-Pressure Metamorphic Rocks

Subduction zones are tectonically active regions that produce seismicity and volcanism during plate convergence and ultimately recycle crustal material into the mantle. Since these regions dictate many global scale tectonic and geochemical processes (i.e. orogenesis, volatile flux into the mantle, etc.), it is important to understand the depth-temperature conditions of mineral reactions during the subduction-exhumation metamorphic cycle. (Ultra)high-pressure ((U)HP) metamorphic rocks, such as blueschists and eclogites, are formed during metamorphism of subducted crust and sediments along relatively cold geothermal gradients. (U)HP metamorphic rocks may be incorporated into the subduction zone accretionary wedge and exhumed, thereby providing a direct records of subduction zone conditions and processes. This PhD research is focused on the determination of pressure (P) – temperature (T) conditions of exhumed (U)HP subduction zone metamorphic rocks in order to better understand the metamorphic conditions of geologic processes within subduction zones. This dissertation contains three separate studies which combine multiple thermobarometric methods to better constrain the petrologic history of exhumed subduction zone metamorphic rocks. Elastic thermobarometry, trace element thermobarometers, and numerical modeling approaches were integrated to determine P–T(–t) histories of (U)HP metamorphic rocks. In the first chapter of this dissertation, multi-diffusion domain numerical modelling of white mica 40Ar/39Ar and thermobarometric data were used to forward model continuous P–T–t paths of blueschist block exhumation from the western Baja terrane of Mexico. Results from this chapter provide new insights into the application of white mica P–T–t numerical modeling to constrain exhumation histories of (U)HP metamorphic rocks. In the second chapter, strain-based quartz-in-garnet elastic thermobarometric data was combined with Ti concentration measurements and a Ti-in-quartz solubility model to estimate P–T conditions of inclusion entrapment in garnet from a quartzofeldspathic gneiss from the (U)HP terrane of eastern Papua New Guinea. The quartz-in-garnet and Ti-in-quartz (QuiG-TiQ) method gives P–T constraints from a single mineral and does not introduce temperature estimates external of the host-inclusion system. Results from this chapter give new insights into the use of elastic thermobarometry to determine conditions of metamorphic mineral growth and inclusion entrapment. In the third chapter, the first characterization of mineralogical evidence for UHP metamorphism in the Appalachian orogen is presented. Multiple thermobarometric methods, including Zr-in-rutile trace element and quartz-in-garnet elastic thermobarometry, were combined with petrologic observations to characterize the prograde metamorphic conditions of garnet growth during subduction

Pose Measurement Performance of the Argon Relative Navigation Sensor Suite in Simulated Flight Conditions

Argon is a flight-ready sensor suite with two visual cameras, a flash LIDAR, an on- board flight computer, and associated electronics. Argon was designed to provide sensing capabilities for relative navigation during proximity, rendezvous, and docking operations between spacecraft. A rigorous ground test campaign assessed the performance capability of the Argon navigation suite to measure the relative pose of high-fidelity satellite mock-ups during a variety of simulated rendezvous and proximity maneuvers facilitated by robot manipulators in a variety of lighting conditions representative of the orbital environment. A brief description of the Argon suite and test setup are given as well as an analysis of the performance of the system in simulated proximity and rendezvous operations

Swarm UAVs for Area Mapping in GPS-denied Locations

Utilizing small Unmanned Aerial Systems (SUAS) in mapping and cartography applications holds transformative potential, particularly in challenging and GPS-denied environments. Traditionally, mapping involved manual efforts using diverse tools, but there has been a fundamental shift towards autonomous vehicles capable of achieving efficient results in less time and with reduced human effort. Autonomous mapping typically relies on single a UAV employing Simultaneous Localization and Mapping (SLAM) or photogrammetry alongside GPS. This research project seeks to leverage swarm robotics to map intricate landscapes and rugged terrains using SUASs with a faster, more accurate, and precise approach, eliminating dependence on GPS for global positioning. The mapping scope encompasses hard-to-access locations like cliffs, abandoned structures, and forests, as well as areas impractical for manual surveying, such as construction sites and expansive indoor spaces like warehouses, factories, or historical buildings resistant to modifications for survey purposes. The swarm will exhibit an emergent-like behavior to map any location efficiently, ensuring collision-free navigation among sUAS and ground objects

Hubble Space Telescope WFC3 Early Release Science: Emission-Line Galaxies from Infrared Grism Observations

We present grism spectra of emission-line galaxies (ELGs) from 0.6-1.6 microns from the Wide Field Camera 3 on the Hubble Space Telescope. These new infrared grism data augment previous optical Advanced Camera for Surveys G800L 0.6-0.95 micron grism data in GOODS-South from the PEARS program, extending the wavelength covereage well past the G800L red cutoff. The ERS grism field was observed at a depth of 2 orbits per grism, yielding spectra of hundreds of faint objects, a subset of which are presented here. ELGs are studied via the Ha, [OIII], and [OII] emission lines detected in the redshift ranges 0.2<z<1.4, 1.2<z<2.2 and 2.0<z<3.3 respectively in the G102 (0.8-1.1 microns; R~210) and G141 (1.1-1.6 microns; R~130) grisms. The higher spectral resolution afforded by the WFC3 grisms also reveals emission lines not detectable with the G800L grism (e.g., [SII] and [SIII] lines). From these relatively shallow observations, line luminosities, star-formation rates, and grism spectroscopic redshifts are determined for a total of 48 ELGs to m(AB)~25 mag. Seventeen GOODS-South galaxies that previously only had photometric redshifts now have new grism-spectroscopic redshifts, in some cases with large corrections to the photometric redshifts (Delta(z)~0.3-0.5). Additionally, one galaxy had no previously-measured redshift but now has a secure grism-spectroscopic redshift, for a total of 18 new GOODS-South spectroscopic redshifts. The faintest source in our sample has a magnitude m(AB)=26.9 mag. The ERS grism data also reflect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample as a function of redshift, consistent with downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes and redshifts to z>2.Comment: Accepted for publication in AJ. Updated to include referee comments. Updated sample using improved reduction contains 23 new galaxies (Table 1; Figures 2 & 3

Higher D or Li: Probes of Physics beyond the Standard Model

Standard Big Bang Nucleosynthesis at the baryon density determined by the microwave anisotropy spectrum predicts an excess of \li7 compared to observations by a factor of 4-5. In contrast, BBN predictions for D/H are somewhat below (but within ~2 \sigma) of the weighted mean of observationally determined values from quasar absorption systems. Solutions to the \li7 problem which alter the nuclear processes during or subsequent to BBN, often lead to a significant increase in the deuterium abundance consistent with the highest values of D/H seen in absorption systems. Furthermore, the observed D/H abundances show considerable dispersion. Here, we argue that those systems with D/H \simeq 4 \times 10^{-5} may be more representative of the primordial abundance and as a consequence, those systems with lower D/H would necessarily have been subject to local processes of deuterium destruction. This can be accounted for by models of cosmic chemical evolution able to destroy in situ Deuterium due to the fragility of this isotope.Comment: 22 pages, 8 figure

Joint effects of climate, tree size, and year on annual tree growth derived from tree-ring records of ten globally distributed forests

Tree rings provide an invaluable long-term record for understanding how climate and other drivers shape tree growth and forest productivity. However, conventional tree-ring analysis methods were not designed to simultaneously test effects of climate, tree size, and other drivers on individual growth. This has limited the potential to test ecologically relevant hypotheses on tree growth sensitivity to environmental drivers and their interactions with tree size. Here, we develop and apply a new method to simultaneously model nonlinear effects of primary climate drivers, reconstructed tree diameter at breast height (DBH), and calendar year in generalized least squares models that account for the temporal autocorrelation inherent to each individual tree\u27s growth. We analyze data from 3811 trees representing 40 species at 10 globally distributed sites, showing that precipitation, temperature, DBH, and calendar year have additively, and often interactively, influenced annual growth over the past 120 years. Growth responses were predominantly positive to precipitation (usually over ≥3-month seasonal windows) and negative to temperature (usually maximum temperature, over ≤3-month seasonal windows), with concave-down responses in 63% of relationships. Climate sensitivity commonly varied with DBH (45% of cases tested), with larger trees usually more sensitive. Trends in ring width at small DBH were linked to the light environment under which trees established, but basal area or biomass increments consistently reached maxima at intermediate DBH. Accounting for climate and DBH, growth rate declined over time for 92% of species in secondary or disturbed stands, whereas growth trends were mixed in older forests. These trends were largely attributable to stand dynamics as cohorts and stands age, which remain challenging to disentangle from global change drivers. By providing a parsimonious approach for characterizing multiple interacting drivers of tree growth, our method reveals a more complete picture of the factors influencing growth than has previously been possible

Prediction of cardiovascular events in rheumatoid arthritis using risk age calculations: evaluation of concordance across risk age models

Background: In younger individuals, low absolute risk of cardiovascular disease (CVD) may conceal an increased risk age and relative risk of CVD. Calculation of risk age is proposed as an adjuvant to absolute CVD risk estimation in European guidelines. We aimed to compare the discriminative ability of available risk age models in prediction of CVD in rheumatoid arthritis (RA). Secondly, we also evaluated the performance of risk age models in subgroups based on RA disease characteristics. Methods: RA patients aged 30?70 years were included from an international consortium named A Trans-Atlantic Cardiovascular Consortium for Rheumatoid Arthritis (ATACC-RA). Prior CVD and diabetes mellitus were exclusión criteria. The discriminatory ability of specific risk age models was evaluated using c-statistics and their standard errors after calculating time until fatal or non-fatal CVD or last follow-up. Results: A total of 1974 patients were included in the main analyses, and 144 events were observed during followup, the median follow-up being 5.0 years. The risk age models gave highly correlated results, demonstrating R2 values ranging from 0.87 to 0.97. However, risk age estimations differed > 5 years in 15?32% of patients. C-statistics ranged 0.68?0.72 with standard errors of approximately 0.03. Despite certain RA characteristics being associated with low c-indices, standard errors were high. Restricting analysis to European RA patients yielded similar results. Conclusions: The cardiovascular risk age and vascular age models have comparable performance in predicting CVD in RA patients. The influence of RA disease characteristics on the predictive ability of these prediction models remains inconclusive

The Seventh Data Release of the Sloan Digital Sky Survey

This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor correction

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected