An empirical model of the quiet daily geomagnetic field variation
Y. Yamazaki, K. Yumoto, M.G. Cardinal, B.J. Fraser, P. Hattori, Y. Kakinami, J.Y. Liu, K.J.W. Lynn, R. Marshall, D. McNamara, T. Nagatsuma, V.M. Nikiforov, R.E. Otadoy, M. Ruhimat, B.M. Shevtsov, K. Shiokawa, S. Abe, T. Uozumi, A. Yoshikawa
2011, Journal of Geophysical Research A: Space Physics (116)
An empirical model of the quiet daily geomagnetic field variation has been constructed based on geomagnetic data obtained from 21 stations along the 210 Magnetic Meridian of the Circum‐pan Pacific Magnetometer Network (CPMN) from 1996 to 2007. Using the least squares fitting method for geomagnetically quiet days (Kp ≤ 2+),...
Habitat suitability and nest survival of white-headed woodpeckers in unburned forests of Oregon
Jeff P. Hollenbeck, Victoria A. Saab, Richard W. Frenzel
2011, Journal of Wildlife Management (75) 1061-1071
We evaluated habitat suitability and nest survival of breeding white-headed woodpeckers (Picoides albolarvatus) in unburned forests of central Oregon, USA. Daily nest-survival rate was positively related to maximum daily temperature during the nest interval and to density of large-diameter trees surrounding the nest tree. We developed a niche-based habitat suitability...
The importance of within-year repeated counts and the influence of scale on long-term monitoring of sage-grouse
B.C. Fedy, Cameron L. Aldridge
2011, Journal of Wildlife Management (75) 1022-1033
Long‐term population monitoring is the cornerstone of animal conservation and management. The accuracy and precision of models developed using monitoring data can be influenced by the protocols guiding data collection. The greater sage‐grouse (Centrocercus urophasianus) is a species of concern that has been monitored over decades, primarily, by counting the...
A bayesian approach for determining velocity and uncertainty estimates from seismic cone penetrometer testing or vertical seismic profiling data
Adam Pidlisecky, Seth S. Haines
2011, Canadian Geotechnical Journal (48) 1061-1069
Conventional processing methods for seismic cone penetrometer data present several shortcomings, most notably the absence of a robust velocity model uncertainty estimate. We propose a new seismic cone penetrometer testing (SCPT) data-processing approach that employs Bayesian methods to map measured data errors into quantitative estimates of model uncertainty. We first...
Effects of temperature changes on maize production in Mozambique
L. Harrison, J. Michaelsen, Chris Funk, G. Husak
2011, Climate Research (46) 211-222
We examined intraseasonal changes in maize phenology and heat stress exposure over the 1979-2008 period, using Mozambique meteorological station data and maize growth requirements in a growing degree-day model. Identifying historical effects of warming on maize growth is particularly important in Mozambique because national food security is highly dependent on...
Status and distribution of the Kittlitz's murrelet Brachyramphus brevirostris in Kenai Fjords, Alaska
Mayumi L. Arimitsu, John F. Piatt, Marc D. Romano, Thomas I. van Pelt
2011, Marine Ornithology: Journal of Seabird Research and Conservation (39) 13-22
The Kittlitz's Murrelet Brachyramphus brevirostris is a candidate species for listing under the US Endangered Species Act because of its apparent declines within core population areas of coastal Alaska. During the summers of 2006-2008, we conducted surveys in marine waters adjacent to Kenai Fjords National Park, Alaska, to estimate the...
Spatial connectivity in a highly heterogeneous aquifer: From cores to preferential flow paths
M. Bianchi, C. Zheng, C. Wilson, G.R. Tick, Gaisheng Liu, S.M. Gorelick
2011, Water Resources Research (47)
This study investigates connectivity in a small portion of the extremely heterogeneous aquifer at the Macrodispersion Experiment (MADE) site in Columbus, Mississippi. A total of 19 fully penetrating soil cores were collected from a rectangular grid of 4 m by 4 m. Detailed grain size analysis was performed on 5...
Magnetic properties in an ash flow tuff with continuous grain size variation: a natural reference for magnetic particle granulometry
J.L. Till, M.J. Jackson, J. G. Rosenbaum, P. Solheid
2011, Geochemistry, Geophysics, Geosystems (12)
The Tiva Canyon Tuff contains dispersed nanoscale Fe-Ti-oxide grains with a narrow magnetic grain size distribution, making it an ideal material in which to identify and study grain-size-sensitive magnetic behavior in rocks. A detailed magnetic characterization was performed on samples from the basal 5 m of the tuff. The magnetic...
Hydrogeomorphic processes of thermokarst lakes with grounded-ice and floating-ice regimes on the Arctic coastal plain, Alaska
C.D. Arp, Benjamin M. Jones, F.E. Urban, G. Grosse
2011, Hydrological Processes (25) 2422-2438
Thermokarst lakes cover > 20% of the landscape throughout much of the Alaskan Arctic Coastal Plain (ACP) with shallow lakes freezing solid (grounded ice) and deeper lakes maintaining perennial liquid water (floating ice). Thus, lake depth relative to maximum ice thickness (1·5–2·0 m) represents an important threshold that impacts permafrost,...
Evaluating the effects of future climate change and elevated CO2 on the water use efficiency in terrestrial ecosystems of China
Q. Zhu, H. Jiang, C. Peng, J. Liu, X. Wei, X. Fang, S. Liu, G. Zhou, S. Yu
2011, Ecological Modelling (222) 2414-2429
Water use efficiency (WUE) is an important variable used in climate change and hydrological studies in relation to how it links ecosystem carbon cycles and hydrological cycles together. However, obtaining reliable WUE results based on site-level flux data remains a great challenge when scaling up to larger regional zones. Biophysical,...
Source and site response study of the 2008 Mount Carmel, Illinois, earthquake
S. Hartzell, C. Mendoza
2011, Bulletin of the Seismological Society of America (101) 951-963
Two separate inversions are performed using the ground-motion data from the 2008 Mount Carmel, Illinois, earthquake. One uses aftershocks as empirical Green’s functions to determine a finite-fault slip distribution. The second uses mainshock ground-motion spectra to calculate source, path, and site response parameters. The slip inversion reveals a prominent asperity...
Estimating California ecosystem carbon change using process model and land cover disturbance data: 1951-2000
Jinxun Liu, James E. Vogelmann, Zhiliang Zhu, Carl H. Key, Benjamin M. Sleeter, D.T. Price, Jing M. Chen, Mark A. Cochrane, Jeffery C. Eidenshink, Stephen M. Howard, Norman B. Bliss, Hong Jiang
2011, Ecological Modelling (222) 2333-2341
Land use change, natural disturbance, and climate change directly alter ecosystem productivity and carbon stock level. The estimation of ecosystem carbon dynamics depends on the quality of land cover change data and the effectiveness of the ecosystem models that represent the vegetation growth processes and disturbance effects. We used...
Evaluation of ground motion scaling methods for analysis of structural systems
A. P. O’Donnell, O.A. Beltsar, Y.C. Kurama, E. Kalkan, A.A. Taflanidis
2011, Conference Paper, Structures Congress 2011 - Proceedings of the 2011 Structures Congress
Ground motion selection and scaling comprises undoubtedly the most important component of any seismic risk assessment study that involves time-history analysis. Ironically, this is also the single parameter with the least guidance provided in current building codes, resulting in the use of mostly subjective choices in design. The relevant research...
Fire frequency, area burned, and severity: A quantitative approach to defining a normal fire year
J.A. Lutz, Carl H. Key, C.A. Kolden, J.T. Kane, Jan W. Van Wagtendonk
2011, Fire Ecology (7) 51-65
Fire frequency, area burned, and fire severity are important attributes of a fire regime, but few studies have quantified the interrelationships among them in evaluating a fire year. Although area burned is often used to summarize a fire season, burned area may not be well correlated with either the number...
Quantification of a greenhouse hydrologic cycle from equatorial to polar latitudes: The mid-Cretaceous water bearer revisited
M.B. Suarez, Luis A. Gonzalez, Greg A. Ludvigson
2011, Palaeogeography, Palaeoclimatology, Palaeoecology (307) 301-312
This study aims to investigate the global hydrologic cycle during the mid-Cretaceous greenhouse by utilizing the oxygen isotopic composition of pedogenic carbonates (calcite and siderite) as proxies for the oxygen isotopic composition of precipitation. The data set builds on the Aptian–Albian sphaerosiderite δ18O data set presented by Ufnar et...
A first look at the petroleum geology of the Lomonosov Ridge microcontinent, Arctic Ocean
Thomas E. Moore, Arthur Grantz, Janet K. Pitman, Philip J. Brown
2011, Geological Society Memoir (35) 751-769
The Lomonosov microcontinent is an elongated continental fragment that transects the Arctic Ocean between North America and Siberia via the North Pole. Although it lies beneath polar pack ice, the geological framework of the microcontinent is inferred from sparse seismic reflection data, a few cores, potential field data and the...
Evaluation of TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis)'s predictive skill for hurricane-triggered landslides: A case study in Macon County, North Carolina
Z. Liao, Y. Hong, D. Kirschbaum, R.F. Adler, J.J. Gourley, R. Wooten
2011, Natural Hazards (58) 325-339
The key to advancing the predictability of rainfall-triggered landslides is to use physically based slope-stability models that simulate the transient dynamical response of the subsurface moisture to spatiotemporal variability of rainfall in complex terrains. TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis) is a USGS landslide prediction model, coded...
Redefinition and global estimation of basal ecosystem respiration rate
W. Yuan, Y. Luo, X. Li, S. Liu, G. Yu, T. Zhou, M. Bahn, A. Black, A.R. Desai, A. Cescatti, B. Marcolla, C. Jacobs, J. Chen, M. Aurela, C. Bernhofer, B. Gielen, G. Bohrer, D.R. Cook, D. Dragoni, A.L. Dunn, D. Gianelle, T. Grnwald, A. Ibrom, M.Y. Leclerc, A. Lindroth, H. Liu, L.B. Marchesini, L. Montagnani, G. Pita, M. Rodeghiero, A. Rodrigues, G. Starr, Paul C. Stoy
2011, Global Biogeochemical Cycles (25) 1-14
Basal ecosystem respiration rate (BR), the ecosystem respiration rate at a given temperature, is a common and important parameter in empirical models for quantifying ecosystem respiration (ER) globally. Numerous studies have indicated that BR varies in space. However, many empirical ER models still use a global constant BR largely due...
Circum-Arctic mapping project: New magnetic and gravity anomaly maps of the Arctic
C. Gaina, S.C. Werner, R. Saltus, S. Maus, S. Aaro, D. Damaske, R. Forsberg, V. Glebovsky, Kevin K. Johnson, J. Jonberger, T. Koren, J. Korhonen, T. Litvinova, G. Oakey, O. Olesen, O. Petrov, M. Pilkington, T. Rasmussen, B. Schreckenberger, M. Smelror
2011, Geological Society Memoir 39-48
New Circum-Arctic maps of magnetic and gravity anomalies have been produced by merging regional gridded data. Satellite magnetic and gravity data were used for quality control of the long wavelengths of the new compilations. The new Circum-Arctic digital compilations of magnetic, gravity and some of their derivatives have been analyzed...
Detecting aseismic strain transients from seismicity data
Andrea L. Llenos, Jeffrey J. McGuire
2011, Journal of Geophysical Research B: Solid Earth (116)
Aseismic deformation transients such as fluid flow, magma migration, and slow slip can trigger changes in seismicity rate. We present a method that can detect these seismicity rate variations and utilize these anomalies to constrain the underlying variations in stressing rate. Because ordinary aftershock sequences often obscure changes in the...
Random variability explains apparent global clustering of large earthquakes
A.J. Michael
2011, Geophysical Research Letters (38)
The occurrence of 5 Mw ≥ 8.5 earthquakes since 2004 has created a debate over whether or not we are in a global cluster of large earthquakes, temporarily raising risks above long-term levels. I use three classes of statistical tests to determine if the record of M ≥ 7 earthquakes...
Forecasting carbon budget under climate change and CO2 fertilization for subtropical region in China using integrated biosphere simulator (IBIS) model
Q. Zhu, H. Jiang, J. Liu, C. Peng, X. Fang, S. Yu, G. Zhou, X. Wei, W. Ju
2011, Polish Journal of Ecology (59) 3-24
The regional carbon budget of the climatic transition zone may be very sensitive to climate change and increasing atmospheric CO2 concentrations. This study simulated the carbon cycles under these changes using process-based ecosystem models. The Integrated Biosphere Simulator (IBIS), a Dynamic Global Vegetation Model (DGVM), was used to evaluate the...
Mapping the distribution of materials in hyperspectral data using the USGS Material Identification and Characterization Algorithm (MICA)
Raymond F. Kokaly, T. V. V. King, Todd M. Hoefen
2011, Conference Paper, International Geoscience and Remote Sensing Symposium (IGARSS)
Identifying materials by measuring and analyzing their reflectance spectra has been an important method in analytical chemistry for decades. Airborne and space-based imaging spectrometers allow scientists to detect materials and map their distributions across the landscape. With new satellite-borne hyperspectral sensors planned for the future, for example, HYSPIRI (HYPerspectral InfraRed...
The application of prototype point processes for the summary and description of California wildfires
K. Nichols, F.P. Schoenberg, Jon E. Keeley, A. Bray, D. Diez
2011, Journal of Time Series Analysis (32) 420-429
A method for summarizing repeated realizations of a space‐time marked point process, known as prototyping, is discussed and applied to catalogues of wildfires in California. Prototype summaries are constructed for varying time intervals using California wildfire data from 1990 to 2006. Previous work on prototypes for temporal and space‐time point...
Evaluation of a black-footed ferret resource utilization function model
D.A. Eads, J.J. Millspaugh, Dean E. Biggins, D.S. Jachowski, T.M. Livieri
2011, Journal of Wildlife Management (75) 1155-1163
Resource utilization function (RUF) models permit evaluation of potential habitat for endangered species; ideally such models should be evaluated before use in management decision‐making. We evaluated the predictive capabilities of a previously developed black‐footed ferret (Mustela nigripes) RUF. Using the population‐level RUF, generated from ferret observations at an adjacent yet...
