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- Description:
- Subglacial water pressures influence groundwater conditions in proximal alpine valley rock slopes, varying with glacier advance and retreat in parallel with changing ice thickness. Fluctuating groundwater pressures in turn increase or reduce effective joint normal stresses, affecting the yield strength of discontinuities. Here we extend simplified assumptions of glacial debuttressing to investigate how glacier loading cycles together with changing groundwater pressures generate rock slope damage and prepare future slope instabilities. Using hydromechanical coupled numerical models closely based on the Aletsch Glacier valley in Switzerland, we simulate Late Pleistocene and Holocene glacier loading cycles including long-term and annual groundwater fluctuations. Measurements of transient subglacial water pressures from ice boreholes in the Aletsch Glacier ablation area, as well as continuous monitoring of bedrock deformation from permanent GNSS stations helps verify our model assumptions. While purely mechanical glacier loading cycles create only limited rock slope damage in our models, introducing a fluctuating groundwater table generates substantial new fracturing. Superposed annual groundwater cycles increase predicted damage. The cumulative effects are capable of destabilizing the eastern valley flank of our model in toppling-mode failure, similar to field observations of active landslide geometry and kinematics. We find that hydromechanical fatigue is most effective acting in combination with long-term loading and unloading of the slope during glacial cycles. Our results demonstrate that hydromechanical stresses associated with glacial cycles are capable of generating substantial rock slope damage and represent a key preparatory factor for paraglacial slope instabilities.
- Keyword:
- Aletsch Glacier, boreholes, numerical models, subglacial water pressure, Switzerland, Late Pleistocene, Holocene, ground water, and geology
- Subject:
- Geology
- Creator:
- Moore, Jeffrey R., Loew, Simon, Limpach, Philippe, Gischig, Valentin, Grämiger, Lorenz, and Funk, Martin
- Owner:
- Jeff Moore
- Based Near Label Tesim:
- Aletsch Glacier, Valais, Switzerland
- Language:
- English
- Date Uploaded:
- 01/03/2020
- Date Modified:
- 10/29/2024
- Date Created:
- Borehole P1 2013-07-12 09:28:09 to 2014-08-08 09:11:14 and Borehole P2: 2013-07-16 05:00:03 to 2014-08-08 22:10:44
- License:
- CC BY NC - Allows others to use and share your data non-commercially and with attribution.
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50D-A50H-3TE4
-
- Description:
- Classification of barrier island morphology stems from the seminal work of M. O. Hayes and others, which linked island shape to tidal range and wave height and defined coastal energy regimes (i.e., wave-dominated, mixed energy, tide-dominated). If true, this general relationship represents a process-based framework to link modern and ancient systems, and is key for determining paleomorphodynamic relationships. Here we present a new semi-global database of barrier islands and spits (n = 702). Shape parameters (aspect, circularity, and roundness) are used to quantify island boundary shape, and assess potential correlation with coastal energy regime using global wave and tide models. In adopting the original energy classification as originally put forth (i.e., wave dominated, wave-influenced mixed, tide-influenced mixed, tide dominated), results show that wave-dominated islands have statistically different mean shape values from those in the mixed energy fields, but the two mixed energy designations are not distinct from each other. Furthermore, each energy regime field contains a wide range of island shapes, with no clear trends present. Linear regression modeling shows that tidal range and wave height account for < 10% of the documented variance in island shape, a strong indication that other controls must be considered. Therefore, while energy regime distinctions can be used descriptively, their utility in predicting and constraining island shape is limited: barrier island shape is not indicative of coastal energy regime, and vice versa. Our analysis also demonstrates empirical scaling relationships among modern barrier islands for the first time, with implications for subsurface prediction. and This is the dataset of the Modern Barrier Island Database published in Mulhern et al., 2017 Marine Geology paper titled "Is Barrier Island Morphology a Function of Wave and Tide Regime?" with the DOI https://doi.org/10.1016/j.margeo.2017.02.016. If using this dataset please cite both the dataset and the paper.
- Keyword:
- paleomorphodynamic relationships, geology, barrier island, shallow marine, island shape, wave-dominated islands, shoreline morphology, Modern Barrier Island Database, and coastal geomorphology
- Subject:
- Geology
- Creator:
- Johnson, Cari L., Mulhern, Julia S., and Martin, John M.
- Owner:
- Julia Mulhern
- Language:
- English
- Date Uploaded:
- 09/08/2021
- Date Modified:
- 06/03/2024
- Date Created:
- 2015-01-01 to 2017-12-31
- License:
- CC BY NC - Allows others to use and share your data non-commercially and with attribution.
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50d-5pzj-r9vr
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- Description:
- While several studies have qualitatively investigated age- and region-dependent adhesion between the vitreous and retina, no studies have directly measured the vitreoretinal strength of adhesion. In this study, we developed a rotational peel device and associated methodology to measure the maximum and steady-state peel forces between the vitreous and the retina. Vitreoretinal adhesion in the equator and posterior pole were measured in human eyes from donors ranging 30 to 79 years of age, and in sheep eyes from premature, neonatal, young lamb, and young adult sheep. In human eyes, maximum peel force in the equator (7.24 ± 4.13 mN) was greater than in the posterior pole (4.08 ± 2.03 mN). This trend was especially evident for younger eyes from donors 30 to 39 years of age. After 60 years of age, there was a significant decrease in the maximum equatorial (4.69 ± 2.52 mN, p = 0.016) and posterior pole adhesion (2.95 ± 1.25 mN, p = 0.037). In immature sheep eyes, maximum adhesion was 7.60 ± 3.06 mN, and did not significantly differ between the equator and posterior pole until young adulthood. At this age, the maximum adhesion in the equator nearly doubled (16.67 ± 7.45 mN) that of the posterior pole, similar to the young adult human eyes. Light microscopy images suggest more disruption of the inner limiting membrane (ILM) in immature sheep eyes compared to adult sheep eyes. Interestingly, in human eyes, ILM disruption was significantly greater in the posterior pole (p < 0.05) and in people over 60 years of age (p < 0.02). These findings supplement the current discussion surrounding age-related posterior vitreous detachment, and the risk factors and physiological progressions associated with this condition. In addition, these data further our understanding of the biomechanical mechanisms of vitreoretinal adhesion, and can be used to develop age- appropriate computational models simulating retinal detachment, hemorrhaging, or retinal trauma. See Creveling CJ, Colter J, Coats B. 2018. Changes in vitreoretinal adhesion with age and region in human and sheep eyes. Frontiers in Bioengineering and Biotechnology 6. https://doi.org/10.3389/fbioe.2018.00153.
- Keyword:
- ophthalmology, retina, vitreous, adhesion, ocular, human, eye, peel test, and sheep
- Subject:
- Quantitative measurement and Vitreoretinal adhesion
- Creator:
- Coats, Brittany and Creveling, Christopher
- Contributor:
- Colter, Jourdan
- Owner:
- BRIAN MCBRIDE
- Based Near Label Tesim:
- Salt Lake City, Utah, United States
- Language:
- English
- Date Uploaded:
- 07/10/2019
- Date Modified:
- 06/03/2024
- Date Created:
- Completed 2017-06-01
- License:
- CC BY – Allows others to use and share your data, even commercially, with attribution.
- Resource Type:
- Image, Dataset, and Video
- Identifier:
- https://doi.org/10.7278/S5BK19H3
-
- Description:
- This dataset is a custom Kraken2 formatted database for the identification of Fungi from shotgun metagenomic data. Kraken2 is a k-mer based read classifier (Wood et al. 2019; https://genomebiology.biomedcentral.com/articles/10.1186/s13059-019-1891-0). The dataset was built with the default k-mer length (k=35) from all publicly available fungal genomes at JGI Mycocosm ( https://mycocosm.jgi.doe.gov/mycocosm/home), and all archaea, bacteria, viral, plasmid, human, fungi, plant, and protozoa genomes, as well as the UniVec Core and nt reference database at NCBI ( https://www.ncbi.nlm.nih.gov/). The reference genomes and sequences were downloaded from JGI and NCBI in March 2020.
- Keyword:
- protozoa, Kraken2 database, plant, bacteria, genomes, fungi, human, archaea, plasmid, and virus
- Subject:
- Mycology and Genomics
- Creator:
- Dentinger, Bryn T. M.
- Owner:
- Bryn Dentinger
- Language:
- English
- Date Uploaded:
- 06/08/2022
- Date Modified:
- 06/03/2024
- Date Created:
- 2020-03-29
- License:
- CC BY NC - Allows others to use and share your data non-commercially and with attribution.
- Resource Type:
- Software or Program Code and Dataset
- Identifier:
- https://doi.org/10.7278/S50d-154b-fppf
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- Description:
- Data were collected from the free online available International Ionosphere Reference (IRI) database ( https://kauai.ccmc.gsfc.nasa.gov/instantrun/iri) for January 1, 2020. The data were then interpolated from 1km to our desired resolution of 0.1km. This is is profile used to simulate the 3D FDTD models to observe the propagation of power line harmonic radiation through the ionosphere.
- Keyword:
- Ionosphere and Inhomogeneous Ionosphere
- Subject:
- FDTD (mathematics), plasmas (physics) , and ionospheric electron density
- Creator:
- Pedgaonkar, Apoorva
- Owner:
- Based Near Label Tesim:
- Salt Lake City, Utah, United States
- Language:
- English
- Date Uploaded:
- 07/12/2024
- Date Modified:
- 09/06/2024
- Date Created:
- 2020-01-20
- License:
- Public Domain – This data is free of copyright restrictions (e.g. government sponsored data).
- Resource Type:
- Dataset
- Identifier:
- http://doi.org/10.7278/S5d-hpp0-g1wy
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- Description:
- This dataset summarizes burial counts according to burial type (free, temporary, or perpetual) for the cemeteries of Père-Lachaise, Montmartre, and Montparnasse in Paris. The data covers the period of 1804 to 1840 and was derived from the digitized daily records of burial for the city of Paris, which are currently held in the Archives de Paris. See Registres journaliers d'inhumation https://archives.paris.fr/r/216/cimetieres). These data are organized by the number of each burial type recorded per page of the digitized records.
- Keyword:
- Paris, burial, Montparnasse, and Pere-Lachaise
- Subject:
- Paris, Montparnasse, and Père-Lachaise, Cimetière du
- Creator:
- Alexander, Kaylee P.
- Owner:
- Kaylee Alexander
- Based Near Label Tesim:
- Paris, Île-de-France, France
- Language:
- English
- Date Uploaded:
- 02/11/2023
- Date Modified:
- 06/03/2024
- Date Created:
- 2019-01-01 to 2021-01-01
- License:
- CC BY NC - Allows others to use and share your data non-commercially and with attribution.
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50d-d18q-yfzt
-
- Description:
- This dataset is based on the 1816, two-volume publication, Le champ du repos, ou le Cimetière Mont-Louis, dit du Père Delachaise. Compiled over the course of 1815 by MM. Roger and Roger (a father-son team), Le champ du repos contains the epitaphs and scale drawing of over 2000 monuments present in the cemetery of Père-Lachaise (Paris, France) by the end of 1815. The author of this dataset has combined the information from this volume (including demographics of the deceased drawn from epitaphs, visual characteristics of monuments, and the locations of monuments within the cemetery) with data from the digitized records of burial available from the Archives de Paris ( https://archives.paris.fr/r/216/cimetieres/). Thus, this dataset details every known monument present in the Cemetery of Père-Lachaise by the end of 1815 with information about the type of burial (free, temporary, or perpetual) that it marked.
- Keyword:
- Paris, France, tombstones, cemeteries, Pere-Lachaise, nineteenth centry, epitaphs, and monuments
- Subject:
- funerary structures, cemeteries, and nineteenth century (dates CE)
- Creator:
- Alexander, Kaylee P.
- Owner:
- Kaylee Alexander
- Language:
- English, French
- Date Uploaded:
- 01/27/2023
- Date Modified:
- 06/05/2024
- Date Created:
- 2021-01-01
- License:
- CC BY NC - Allows others to use and share your data non-commercially and with attribution.
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50d-4cbs-yrv1
-
- Description:
- Micrometer-scale maps of authigenic microstructures in submarine basaltic tuff from a 1979 Surtsey volcano, Iceland, drill core acquired 15 years after eruptions terminated describe the initial alteration of oceanic basalt in a low temperature hydrothermal system. An integrative investigative approach uses synchrotron source X-ray microdiffraction (µXRD), microfluoresence (µXRF), micro-computed tomography (µCT), and scanning transmission electron microscopy (S/TEM) coupled with Raman spectroscopy to create finely resolved spatial frameworks that record a continuum of alteration in glass and olivine. Micro-analytical maps of vesicular and fractured lapilli in specimens from 157.1, 137.9, and 102.6 m depth, and borehole temperatures of 83, 93.9 and 141.3 °C measured in 1980, respectively, describe the production of nanocrystalline clay mineral, zeolites, and Al-tobermorite in diverse microenvironments. Irregular alteration fronts at 157.1 m depth resemble microchannels associated with biological activity in older basalts. By contrast, linear microstructures with little resemblance to previously described alteration features have nanocrystalline clay mineral (nontronite) and zeolite (amicite) texture. The crystallographic preferred orientation rotates around an axis parallel to the linear feature. Raman spectra indicating degraded and poorly-ordered carbonaceous matter of possible biological origin are associated with nanocrystalline clay mineral in a crystallographically-oriented linear microstructure in altered olivine at 102.6 m and with sub-circular nanoscale cavities in altered glass at 137.9 m depth. Although evidence for biotic processes is inconclusive, the integrated analyses describe the complex organization of previously unrecognized mineral texture in very young basalt. They provide a foundational mineralogical reference for longitudinal, time-lapse characterizations of palagonitized basalt in oceanic environments.
- Keyword:
- micrometer-scale maps, x-ray microdiffraction, glass alteration, Surtsey Volcano, and submarine basalt
- Subject:
- volcanology
- Creator:
- Couper, Samantha, Parkinson, Dula, Miyagi, Lowell M. , Czabaj, Michael W., Stan, Camelia V. , Moore, James G. , Ivarsson, Magnus, Jackson, Marie D., and Tamura, Nobumichi
- Owner:
- BRIAN MCBRIDE
- Based Near Label Tesim:
- Surtsey, South, Iceland
- Language:
- English
- Date Uploaded:
- 07/11/2019
- Date Modified:
- 10/03/2024
- Date Created:
- 2016-01-01 to 2019-07-11
- License:
- CC BY NC - Allows others to use and share your data non-commercially and with attribution.
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50D-VJND-8V00
-
- Description:
- Forests play a major role in the global carbon cycle. Previous studies on the capacity of forests to sequester atmospheric CO2 have mostly focused on carbon uptake, but the roles of carbon turnover time and its spatiotemporal changes remain poorly understood. Here, we used long-term inventory data (1955-2018) from 695 mature forest plots to quantify temporal trends in living vegetation carbon turnover time across tropical, temperate, and cold climate zones, and compared plot data to eight Earth system models (ESMs). Long-term plots consistently showed decreases in living vegetation carbon turnover time, likely driven by increased tree mortality across all major climate zones. Changes in living vegetation carbon turnover time were negatively correlated with CO2 enrichment in both forest plot data and ESM simulations. However, plot-based correlations between living vegetation carbon turnover time and climate drivers such as precipitation and temperature diverged from those of ESM simulations. Our analyses suggest that forest carbon sinks are likely to be constrained by a decrease in living vegetation carbon turnover time, and accurate projections of forest carbon sink dynamics will require an improved representation of tree mortality processes and their sensitivity to climate in ESMs.
- Keyword:
- tree mortality, forest carbon stocks, carbon turnover, forest productivity, cold climate zone, tropical climate zone, climate change, carbon cycle, temperate climate zone, and earth system models
- Subject:
- Forestry
- Creator:
- Anderegg, William R.L., Schraub, Marcus, Yu, Kailiang, Gessler, Arthur, Penuelas, Josep, Cailleret, Maxine, Peng, Changhui, Condit, Richard, Ferretti, Marco, Hubbell, Stephen P., Smith, William K., Sardans, Jordi, Levanic, Tom, Zhu, Kai, and Trugman, Anna T.
- Owner:
- KAILIANG YU
- Language:
- English
- Date Uploaded:
- 10/24/2019
- Date Modified:
- 10/29/2024
- Date Created:
- 2018–2019
- License:
- CC BY NC - Allows others to use and share your data non-commercially and with attribution.
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/doi:10.7278/S50D-D656-FSP2
-
- Description:
- This study investigates impacts of altering subgrid-scale mixing in “convection-permitting” km-scale horizontal grid spacing (∆h) simulations by applying either constant or stochastic multiplicative factors to the horizontal mixing coefficients within the Weather Research and Forecasting model. In quasi-idealized 1-km ∆h simulations of two observationally based squall line cases, constant enhanced mixing produces larger updraft cores that are more dilute at upper levels, weakens the cold pool, rear inflow jet, and front-to-rear flow of the squall line, and degrades the model’s effective resolution. Reducing mixing by a constant multiplicative factor has the opposite effect on all metrics. Completely turning off parameterized horizontal mixing produces bulk updraft statistics and squall line mesoscale structure closest to a LES “benchmark” among all 1-km simulations, although the updraft cores are too undilute. The stochastic mixing scheme, which applies a multiplicative factor to the mixing coefficients that varies stochastically in time and space, is employed at 0.5-, 1-, and 2-km ∆h. It generally reduces mid-level vertical velocities and enhances upper-level vertical velocities compared to simulations using the standard mixing scheme, with more substantial impacts at 1-km and 2-km ∆h compared to 0.5-km. The stochastic scheme also increases updraft dilution to better agree with the LES for one case, but has less impact on the other case. Stochastic mixing acts to weaken the cold pool but without a significant impact on squall line propagation. It also does not affect the model’s overall effective resolution unlike applying constant multiplicative factors to the mixing coefficients.
- Keyword:
- stochastic, stochastic mixing, WRF, squall line, simulation, weather research and forecasting, and mixing
- Subject:
- Atmospheric Sciences
- Creator:
- Stanford, McKenna, Morrison, Hugh, and Varble, Adam
- Owner:
- MCKENNA STANFORD
- Language:
- English
- Date Uploaded:
- 08/17/2020
- Date Modified:
- 10/29/2024
- Date Created:
- 2019-03-01 to 2020-04-30
- License:
- Public Domain – This data is free of copyright restrictions (e.g. government sponsored data).
- Resource Type:
- Dataset
- Identifier:
- https://doi.org/10.7278/S50DJNGQ6V67