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223 records · Page 13Linked to original sources
USGS2024

Developing a photography-based harvest survey to estimate age and subspecies composition of midcontinent sandhill cranes

Midcontinent sandhill cranes ( Antigone canadensis ) are managed as a single population, but hunting regulations are structured so harvest is targeted towards the more numerous lesser sandhill cranes ( A. c. canadensis ). However, research indicates that greater sandhill cranes ( A. c. tabida ) have been disproportionally exposed to harvest at a rate exceeding their proportion within the midcontinent population. In addition, harvest has increased 22% per year in the U.S. Central Flyway states. The midcontinent population appears to be growing in recent years, but variability in annual abundance estimates has increased substantially. With limited resources and harvest management uncertainty increasing, we developed methods for a citizen science, photography-based harvest survey to estimate age and subspecies composition of harvested midcontinent sandhill cranes. To develop survey methods, we collected physical parts from 284 sandhill cranes in North Dakota in 2019 and 2020. We manually measured the culmen and tarsus using calipers, and digitally measured these parts using photographs and computer software. All digitally derived measurements were 2.5% to 5.9% larger than manual measurements; therefore, we developed linear models that adjusted digital measurements, facilitating subspecies prediction using an existing morphometric-based technique. In 2021, we requested an equal number of hunters to participate using 2 data collection methods to test if hunters could reliably take photographs suitable for digital measurement. Collection method 1 involved photographing the head and leg simultaneously, and Collection method 2 involved photographing the head only. Hunters submitted a total of 239 photographs. Only 80 of these photographs were submitted using Collection method 1, and 72% were suitable for digital measurement. Conversely, hunters submitted twice as many photographs using Collection method 2, and 88% of these photographs were deemed suitable. Although obtaining the tarsus measurement slightly improved subspecies predictability, Collection method 2 increased participation and usable data. We believe our results could be used to develop an operational survey of age and subspecies composition of midcontinent sandhill cranes, wherein a sample of crane hunters throughout the midcontinent population range would be asked to electronically submit a photograph of the head of each bird they harvest. A time series of age and subspecies composition of this population would provide managers with valuable information and improve harvest management at minimal additional cost and burden, compared to a traditional parts collection survey administered by mail.

Wildlife Society Bulletin↗
USGS2021

The AEMON-J “Hacking Limnology” workshop series & virtual summit: Incorporating data science and open science in aquatic research

Following the 2020 “Virtual Summit: Incorporating Data Science and Open Science in Aquatic Research” (DSOS; Meyer and Zwart 2020 ), a grassroots group of scientists convened the 2nd Virtual DSOS Summit on 22–23 July 2021. DSOS combined forces with the Aquatic Ecosystem MOdeling Network - Junior (AEMON-J; https://github.com/aemon-j) to host a 4-d “Hacking Limnology” Workshop Series prior to the summit (13–16 July 2021). The aim was to focus more deeply on skill development and networking among early career researchers (ECRs), both of which are key to growing a workforce of data-intensive aquatic scientists (López Moreira M et al. in press; Meyer et al. 2021 a ). To support ECRs further, we hosted a virtual job board, where participants could note if they were either looking for employment or hiring for a position. Like the 2020 summit, there was high enthusiasm for both the summit and the workshops. In total, 686 people from over 50 countries registered for the AEMON-J Workshop Series and the DSOS Summit. Countries with the highest number of registrants included the United States (41%), Nigeria (20%), Canada (6%), Brazil (6%), and Germany (5%) (Fig. 1). To increase accessibility, there were no registration costs for the workshops and summit, and we centralized introductory training materials, coding scripts, and presentation recordings in one community website (https://aquaticdatasciopensci.github.io/; Fig. 2), which we hope will continue to support the AEMON-J and DSOS communities over time.

Limnology and Oceanography Bulletin↗
USGS2021

A Next Generation Lunar Orbiter mission

The Moon is the scientific foundation for our knowledge of the early evolution and impact history of the terrestrial planets. Over the last decades the lunar science community has made significant progress in addressing key lunar science and exploration goals, while defining many new high-priority scientific questions regarding the formation and evolution of the Moon. On a broad scale, the last Planetary Decadal Survey defined three scientific objectives to guide studies of the inner planets and Moon. These objectives address the origins and diversity of terrestrial planets, the evolution of life on terrestrial planets, and climate processes on Earth-like planets [1]. Many of these objectives carry forward into exploration goals of a renewed lunar human exploration program, and urgently addressing these objectives will enable the rapid development of exploration plans. A large (Flagship or New Frontiers class) Next Generation Lunar Orbiter (NGLO) mission would address the last Planetary Decadal Survey objective of understanding the origin and diversity of terrestrial planets by studying the geochemistry and geology of the Moon at an unparalleled resolution compared to other lunar mission datasets. Also, NGLO would address the objective of studying the evolution of life on terrestrial planets by furthering knowledge about the composition and distribution of volatile elements on the lunar surface and better characterizing the past and present-day impact rates in the inner Solar System in order to better understand the original delivery of water to Earth. Key exploration goals, including identifying the nature and distribution of lunar volatiles (i.e., water, ice), mapping and characterizing potentially valuable lunar resources, and establishing a human presence on the Moon, also would be addressed by NGLO.

Bulletin of the AAS↗
USGS2025

Overview of The SCEC/USGS Community Stress Drop Validation Study using the 2019 Ridgecrest earthquake sequence

We present initial findings from the ongoing Community Stress Drop Validation Study to compare spectral stress‐drop estimates for earthquakes in the 2019 Ridgecrest, California, sequence. This study uses a unified dataset to independently estimate earthquake source parameters through various methods. Stress drop, which denotes the change in average shear stress along a fault during earthquake rupture, is a critical parameter in earthquake science, impacting ground motion, rupture simulation, and source physics. Spectral stress drop is commonly derived by fitting the amplitude‐spectrum shape, but estimates can vary substantially across studies for individual earthquakes. Sponsored jointly by the U.S. Geological Survey and the Statewide (previously, Southern) California Earthquake Center our community study aims to elucidate sources of variability and uncertainty in earthquake spectral stress‐drop estimates through quantitative comparison of submitted results from independent analyses. The dataset includes nearly 13,000 earthquakes ranging from M 1 to 7 during a two‐week period of the 2019 Ridgecrest sequence, recorded within a 1° radius. In this article, we report on 56 unique submissions received from 20 different groups, detailing spectral corner frequencies (or source durations), moment magnitudes, and estimated spectral stress drops. Methods employed encompass spectral ratio analysis, spectral decomposition and inversion, finite‐fault modeling, ground‐motion‐based approaches, and combined methods. Initial analysis reveals significant scatter across submitted spectral stress drops spanning over six orders of magnitude. However, we can identify between‐method trends and offsets within the data to mitigate this variability. Averaging submissions for a prioritized subset of 56 events shows reduced variability of spectral stress drop, indicating overall consistency in recovered spectral stress‐drop values.

California↗
USGS2024

Geological context and significance of the clay-sulfate transition region in Mount Sharp, Gale crater, Mars: An integrated assessment based on orbiter and rover data

On Mars, phyllosilicate (“clay”) minerals are often associated with older terrains, and sulfate minerals are associated with younger terrains, and this dichotomy is taken as evidence that Mars’ surface dried up over time. Therefore, in situ investigation of the Mount Sharp strata in Gale crater, which record a shift from dominantly clay-bearing to sulfate-bearing minerals, as seen in visible−near-infrared orbital reflectance spectra, is a key science objective for the Mars Science Laboratory (MSL) Curiosity rover mission. Here, we present regional (orbiter-based) and in situ (rover-based) evidence for a low-angle erosional unconformity that separates the lacustrine and marginal lacustrine deposits of the Carolyn Shoemaker formation from the dominantly eolian deposits of the lower Mirador formation within the orbitally defined clay-sulfate transition region. The up-section record of wetter (Carolyn Shoemaker formation) to drier (lower Mirador formation) depositional conditions is accompanied by distinct changes in diagenesis. Clay minerals occur preferentially within the Carolyn Shoemaker formation and are absent within the lower members of the Mirador formation. At and above the proposed unconformity, strata are characterized by an increase in diagenetic nodules enriched in X-ray amorphous Mg-sulfate. Early clay formation in the Carolyn Shoemaker formation may have created a hydraulic barrier such that later migrating magnesium- and sulfur-rich fluids accumulated preferentially within the lower members of the Mirador formation. The proposed unconformity may have also acted as a fluid conduit to further promote Mg-sulfate nodule formation at the Carolyn Shoemaker−Mirador formation boundary. These results confirm an association of the clay-sulfate transition with the drying of depositional environments, but they also suggest that at least some orbital sulfate signatures within the region are not time-congruent with the environmental signals extracted from primary sedimentology. Our findings highlight that complex interactions among primary depositional environment, erosion, and diagenesis contribute to the transition in clay-sulfate orbital signatures observed in the stratigraphy of Mount Sharp.

GSA Bulletin↗
USGS2014

Barcodes are a useful tool for labeling and tracking ecological samples

Barcodes are used to label and track just about everything these days. Look around your office, in your medicine cabinet, at the package you just received in the mail, or on the shelves of any shop in town, and you will immediately grasp the ubiquity of their use. Interestingly, railroads and supermarkets were the early pioneers of barcode development: the former needing a way to track railway car location and ownership on a national scale, the latter needing a way to track a diverse array of products and to decrease checkout times (Nelson 1997). Barcodes first came to use in the sciences via the field of medicine, and the medical literature contains hundreds of publications describing how this technology has reduced errors in patient specimen identification and handling, where error mitigation is crucial. In short, barcodes have been adopted by many industries, and in many fields they are now synonymous with asset tracking. In spite of their potential to efficiently organize “assets” (i.e., samples) and minimize human error, the use of barcodes has yet to gain widespread application in ecology. In an age where students take notes on laptops instead of paper, and where “text messaging” involves a smartphone rather than a ball‐point pen, why do otherwise tech‐savvy ecologists persist in hand‐labeling samples? Why do we repeatedly transcribe long and unique identifiers at each step in the process of sample analysis, thereby wasting time and creating opportunities for transcription errors and data loss? Why are most sample storage areas only successfully navigable by the lab manager who personally shelved the samples? In the case of our large ecology lab—and, we suspect, in many others as well—the answer to these questions was perpetually, “bar‐coding won't be worth the trouble.” Recently, however, we realized this was no longer a sufficient answer when we started a new research project that involved collecting an additional thousands of samples each year; we decided to embrace the tangible benefits of an electronic labeling system, and implemented barcoding in our lab. To be clear, the use of barcoding in ecology is not completely novel, and there have been early adopters of this technology. For example, the Cedar Creek Long Term Ecological Research (LTER) site has been using barcodes since at least the mid‐1990s to track the large number of samples collected in their long‐term experimental grasslands (T. A. Kennedy, personal observation ). Overall, however, Cedar Creek is an outlier: in informal e‐mail surveys of LTER sites, only two of eight respondents used barcodes for sample identification or tracking, and even then their use was generally limited to certain samples or certain stages of sample analysis. Our objective in this article is to use our lab as a case study to highlight the potential of barcodes to simplify numerous aspects of sample collection and processing.

Arizona↗
USGS1994

Airborne remote sensing for geology and the environment; present and future

In 1988, a group of leading experts from government, academia, and industry attended a workshop on airborne remote sensing sponsored by the U.S. Geological Survey (USGS) and hosted by the Branch of Geophysics. The purpose of the workshop was to examine the scientific rationale for airborne remote sensing in support of government earth science in the next decade. This report has arranged the six resulting working-group reports under two main headings: (1) Geologic Remote Sensing, for the reports on geologic mapping, mineral resources, and fossil fuels and geothermal resources; and (2) Environmental Remote Sensing, for the reports on environmental geology, geologic hazards, and water resources. The intent of the workshop was to provide an evaluation of demonstrated capabilities, their direct extensions, and possible future applications, and this was the organizational format used for the geologic remote sensing reports. The working groups in environmental remote sensing chose to present their reports in a somewhat modified version of this format. A final section examines future advances and limitations in the field. There is a large, complex, and often bewildering array of remote sensing data available. Early remote sensing studies were based on data collected from airborne platforms. Much of that technology was later extended to satellites. The original 80-m-resolution Landsat Multispectral Scanner System (MSS) has now been largely superseded by the 30-m-resolution Thematic Mapper (TM) system that has additional spectral channels. The French satellite SPOT provides higher spatial resolution for channels equivalent to MSS. Low-resolution (1 km) data are available from the National Oceanographic and Atmospheric Administration's AVHRR system, which acquires reflectance and day and night thermal data daily. Several experimental satellites have acquired limited data, and there are extensive plans for future satellites including those of Japan (JERS), Europe (ESA), Canada (Radarsat), and the United States (EOS). There are currently two national airborne remote sensing programs (photography, radar) with data archived at the USGS' EROS Data Center. Airborne broadband multispectral data (comparable to Landsat MSS and TM but involving several more channels) for limited geographic areas also are available for digital processing and analysis. Narrow-band imaging spectrometer data are available for some NASA experiment sites and can be acquired for other locations commercially. Remote sensing data and derivative images, because of the uniform spatial coverage, availability at different resolutions, and digital format, are becoming important data sets for geographic information system (GIS) analyses. Examples range from overlaying digitized geologic maps on remote sensing images and draping these over topography, to maps of mineral distribution and inferred abundance. A large variety of remote sensing data sets are available, with costs ranging from a few dollars per square mile for satellite digital data to a few hundred dollars per square mile for airborne imaging spectrometry. Computer processing and analysis costs routinely surpass these expenses because of the equipment and expertise necessary for information extraction and interpretation. Effective use requires both an understanding of the current methodology and an appreciation of the most cost-effective solution.

Bulletin↗