Propagation Of Long Fractures In The Ronne Ice Shelf Investigated Using A Numerical Model Of Fracture Propagation, 2010 Portland State University
Propagation Of Long Fractures In The Ronne Ice Shelf Investigated Using A Numerical Model Of Fracture Propagation, Christina L. Hulbe, Christine Marie Ledoux, Kenneth M. Cruikshank
Geology Faculty Publications and Presentations
Long rifts near the front of the Ronne Ice Shelf, Antarctica, are observed to begin as fractures along the lateral boundaries of outlet streams feeding the shelf. These flaws eventually become the planes along which tabular icebergs calve. The fractures propagate laterally as they advect through the shelf, with orientations that can be explained by the glaciological stress field. Fracture length remains constrained over much of the advective path, and locations of crack tip arrest are observed to coincide with structural boundaries, such as suture zones between ice from adjacent outlet glaciers. Geomechanical principles and numerical models demonstrate that in ...
Women In Glaciology, An Historical Perspective, 2010 Portland State University
Women In Glaciology, An Historical Perspective, Christina L. Hulbe, Weili Wang, Simon Ommanney
Geology Faculty Publications and Presentations
Women's history in glaciology extends as far back in time as the discipline itself, although their contributions to the scientific discourse have for all of that history been constrained by the sociopolitical contexts of the times. The first Journal of Glaciology paper authored by a woman appeared in 1948, within a year of the founding of the Journal, but it was not until the 1980s that women produced more than a few percent of Journal and Annals of Glaciology papers. Here international perspectives on women's participation in the sciences are presented in order to establish an economic and ...
To The Ice: George Bird Grinnell's 1887 Ascent Of Grinnell Glacier, 2010 Indiana University Maurer School of Law
To The Ice: George Bird Grinnell's 1887 Ascent Of Grinnell Glacier, Richard Vaughan
Articles by Maurer Faculty
This article discusses a climbing expedition undertaken by U.S. conservationist George Bird Grinnell to ascend what would come to be known as Grinnell Glacier in Montana. Grinnell’s efforts to establish Glacier National Park are detailed. Grinnell’s previously unpublished descriptions of the glacier and its surrounding area are analyzed by the author.
Post-Coring Entrapment Of Modern Air In Some Shallow Ice Cores Collected Near The Firn-Ice Transition: Evidence From Cfc-12 Measurements In Antarctic Firn Air And Ice Cores, 2010 University of California - Irvine
Post-Coring Entrapment Of Modern Air In Some Shallow Ice Cores Collected Near The Firn-Ice Transition: Evidence From Cfc-12 Measurements In Antarctic Firn Air And Ice Cores, Murat Aydin, S. A. Montzka, M. O. Battle, M. B. Williams, Warren J. De Bruyn, J. H. Butler, K. R. Verhulst, C. Tatum, B. K. Gun, D. A. Plotkin, B. D. Hall, Eric S. Saltzman
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
In this study, we report measurements of CFC-12 (CCl2F2) in firn air and in air extracted from shallow ice cores from three Antarctic sites. The firn air data are consistent with the known atmospheric history of CFC-12. In contrast, some of the ice core samples collected near the firn-ice transition exhibit anomalously high CFC-12 levels. Together, the ice core and firn air data provide evidence for the presence of modern air entrapped in the shallow ice core samples that likely contained open pores at the time of collection. We propose that this is due to closure of the open pores ...
Climate In The Southern Sawatch Range And Elk Mountains, Colorado, U.S.A., During The Last Glacial Maximum: Inferences Using A Simple Degree-Day Model, 2010 University of Minnesota, Morris
Climate In The Southern Sawatch Range And Elk Mountains, Colorado, U.S.A., During The Last Glacial Maximum: Inferences Using A Simple Degree-Day Model, Keith A. Brugger
Equilibrium-line altitudes (ELAs) were determined from reconstructions of 22 paleoglaciers at their extent during the local last glacial maximum (LGM) using the accumulation-area method. LGM ELAs thus derived ranged from 2980 to 3560 m and follow a statistically significant regional trend of rising ~4.5 m km-1 to the east. Two approaches using a degree-day model were used to infer LGM climate by finding plausible combinations of temperature and precipitation change that (1) would be required to lower ELAs to their mean LGM values in both the Taylor Park/eastern Elk Mountains region and western Elk Mountains, and (2 ...