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ASU Scholarship Showcase


This growing collection consists of scholarly works authored by ASU-affiliated faculty, students and community members, and contains many open access articles. ASU-affiliated authors are encouraged to Share Your Work in the ASU Digital Repository.


Contributor
Date Range
2011 2018


The southern Tibetan Plateau margin between ~ 83E and 86.5E is defined by an abrupt change from the low-relief Tibetan Plateau to the rugged topography and deep gorges of the Himalaya. This physiographic transition lies well to the north of active thrusting, and thus, the mechanism responsible for the distinct topographic break remains the focus of much debate. While numerous studies have utilized thermochronology to examine the exhumation history of the Himalaya, few have done so with respect to variations across the Himalaya-Tibetan Plateau transition. In this work, we examine the nature of the transition where it is accessible and …

Contributors
McDermott, Jeni, Whipple, Kelin, Hodges, Kip, et al.
Created Date
2013-05-30

We present a model explaining the elemental enrichments in Jupiter's atmosphere, particularly the noble gases Ar, Kr, and Xe. While He, Ne, and O are depleted, seven other elements show similar enrichments (~3 times solar, relative to H). Being volatile, Ar is difficult to fractionate from H[subscript 2]. We argue that external photoevaporation by far-ultraviolet (FUV) radiation from nearby massive stars removed H[subscript 2], He, and Ne from the solar nebula, but Ar and other species were retained because photoevaporation occurred at large heliocentric distances where temperatures were cold enough (lesssim 30 K) to trap them in amorphous water ice. …

Contributors
Monga, Nikhil, Desch, Steven, College of Liberal Arts and Sciences, et al.
Created Date
2015-01-01

Ferromagnetic Heusler Co[subscript 2]FeAl[subscript 0.5]Si[subscript 0.5] epitaxial thin-films have been fabricated in the L2[subscript 1] structure with saturation magnetizations over 1200 emu/cm[superscript 3]. Andreev reflection measurements show that the spin polarization is as high as 80% in samples sputtered on unheated MgO (100) substrates and annealed at high temperatures. However, the spin polarization is considerably smaller in samples deposited on heated substrates.

Contributors
Vahidi, Mahmoud, Gifford, Jessica, Zhang, Shengke, et al.
Created Date
2014-04-15

Context. Clusters of galaxies provide valuable information on the evolution of the Universe and large scale structures. Recent cluster observations via the thermal Sunyaev-Zel’dovich (tSZ) effect have proven to be a powerful tool to detect and study them. In this context, high resolution tSZ observations (~tens of arcsec) are of particular interest to probe intermediate and high redshift clusters. Aims. Observations of the tSZ effect will be carried out with the millimeter dual-band NIKA2 camera, based on kinetic inductance detectors (KIDs) to be installed at the IRAM 30-m telescope in 2015. To demonstrate the potential of such an instrument, we …

Contributors
Adam, R., Comis, B., Macias-Perez, J. F., et al.
Created Date
2014-09-01

The highest elevation of the Tibetan Plateau, lying 5,700 m above sea level, occurs within the part of the Lhasa block immediately north of the India-Tibet suture zone (Yarlung Zangbo suture zone, YZSZ), being 700 m higher than the maximum elevation of more northern parts of the plateau. Various mechanisms have been proposed to explain this differentially higher topography and the rock uplift that led to it, invoking crustal compression or extension. Here we present the results of structural investigations along the length of the high elevation belt and suture zone, which rather indicate flexural bending of the southern margin …

Contributors
Wang, Erchie, Kamp, Peter J. J., Xu, Ganqing, et al.
Created Date
2015-07-15

It is commonly anticipated that gravity is subjected to the standard principles of quantum mechanics. Yet some — including Einstein — have questioned that presumption, whose empirical basis is weak. Indeed, recently Dyson has emphasized that no conventional experiment is capable of detecting individual gravitons. However, as we describe, if inflation occurred, the universe, by acting as an ideal graviton amplifier, affords such access. It produces a classical signal, in the form of macroscopic gravitational waves, in response to spontaneous (not induced) emission of gravitons. Thus recent BICEP2 observations of polarization in the cosmic microwave background (CMB) will, if confirmed, …

Contributors
Krauss, Lawrence, Wilczek, Frank, College of Liberal Arts and Sciences, et al.
Created Date
2014-10-01

The Dawn Framing Camera (FC) has imaged the northern hemisphere of the Asteroid (4) Vesta at high spatial resolution and coverage. This study represents the first investigation of the overall geology of the northern hemisphere (22–90°N, quadrangles Av-1, 2, 3, 4 and 5) using these unique Dawn mission observations. We have compiled a morphologic map and performed crater size–frequency distribution (CSFD) measurements to date the geologic units. The hemisphere is characterized by a heavily cratered surface with a few highly subdued basins up to ∼200 km in diameter. The most widespread unit is a plateau (cratered highland unit), similar to, …

Contributors
Ruesch, Ottaviano, Hiesinger, Harald, Blewett, David T., et al.
Created Date
2014-12-01

Oppia Quadrangle Av-10 (288–360°E, ±22°) is a junction of key geologic features that preserve a rough history of Asteroid (4) Vesta and serves as a case study of using geologic mapping to define a relative geologic timescale. Clear filter images, stereo-derived topography, slope maps, and multispectral color-ratio images from the Framing Camera on NASA’s Dawn spacecraft served as basemaps to create a geologic map and investigate the spatial and temporal relationships of the local stratigraphy. Geologic mapping reveals the oldest map unit within Av-10 is the cratered highlands terrain which possibly represents original crustal material on Vesta that was then …

Contributors
Garry, W. Brent, Williams, David, Yingst, R. Aileen, et al.
Created Date
2014-12-01

We report on a preliminary global geologic map of Vesta, based on data from the Dawn spacecraft’s High-Altitude Mapping Orbit (HAMO) and informed by Low-Altitude Mapping Orbit (LAMO) data. This map is part of an iterative mapping effort; the geologic map has been refined with each improvement in resolution. Vesta has a heavily-cratered surface, with large craters evident in numerous locations. The south pole is dominated by an impact structure identified before Dawn’s arrival. Two large impact structures have been resolved: the younger, larger Rheasilvia structure, and the older, more degraded Veneneia structure. The surface is also characterized by a …

Contributors
Yingst, R. A., Mest, S. C., Berman, D. C., et al.
Created Date
2014-11-15

Vesta is a unique, intermediate class of rocky body in the Solar System, between terrestrial planets and small asteroids, because of its size (average radius of ∼263 km) and differentiation, with a crust, mantle and core. Vesta’s low surface gravity (0.25 m/s[superscript 2]) has led to the continual absence of a protective atmosphere and consequently impact cratering and impact-related processes are prevalent. Previous work has shown that the formation of the Rheasilvia impact basin induced the equatorial Divalia Fossae, whereas the formation of the Veneneia impact basin induced the northern Saturnalia Fossae. Expanding upon this earlier work, we conducted photogeologic …

Contributors
Scully, Jennifer E. C., Yin, A., Russell, C. T., et al.
Created Date
2014-01-29