Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Article”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
USGS2021

Reply to “comment on ‘which earthquake accounts matter?’ by Susan E. Hough and Stacey S. Martin” by David J. Wald

We thank David Wald ( Wald, 2021 ; henceforth, W21) for his interest in our recent article ( Hough and Martin, 2021 ; henceforth, HM21). Although different perspectives are vital in science, we are concerned that W21 misrepresents HM21 as an oblique criticism of the U.S. Geological Survey “Did You Feel It?” (DYFI) system, calling for HM21 to be retracted. Readers who are interested in the issues raised by HM21 and the statements made by us therein are referred to that article. In this brief reply, we respond to specific accusations made by W21 and return to the focus of HM21, calling attention to the extent to which macroseismic data sets and inferences drawn from them can be shaped by a lack of representation among individuals whose observations are available to science. HM21 never questioned the benefits of the community science DYFI project to science. HM21 noted, however, and we reiterate here, that community science also potentially benefits the community. Whether or not it matters for science, if participation in community science projects is unrepresentative across socioeconomic groups, it underscores the need for the scientific community to be proactive in its efforts to reach out to groups that have been underserved by current outreach and education programs. We appreciate this opportunity to continue the important conversation about representation.

Seismological Research Letters↗
USGS2025

REDPy: A Python tool for automated repeating earthquake detection and visualization

Detecting and cataloging seismic events are among the most fundamental tasks in seismology. Many standardized tools for these tasks exist, including the open‐source package repeating earthquake detector in Python (REDPy). REDPy generates an organized catalog of seismic events from continuous waveform data, in which events are automatically separated into groups (“families”) by their waveform similarity through cross‐correlation. REDPy also automatically generates various outputs that allow a user to visualize important trends in the catalog, which may be used in real time or in retrospective analyses to allow rapid identification of interesting features. The code was designed for near‐real‐time volcano monitoring but is applicable across a broad range of use cases in seismology and seismoacoustics. In this article, the utility and performance of REDPy are demonstrated on two highly seismogenic volcanic eruption sequences: the onset of the dome‐building eruption of Mount St. Helens, Washington, from 2004 to 2005, and the entirety of the summit caldera collapse sequence of Kīlauea, Hawai‘i, in 2018. This article is meant to be a companion to the documentation of the code; in addition to detailing the basic required inputs, script functionality, and resulting outputs, the reasonings behind several important design decisions are also discussed.

Seismological Research Letters↗
USGS2026

Erratum to earthquake recurrence estimates for northern Caribbean faults from combinatorial optimization

In the original article (ten Brink and Geist, 2025), we derived on‐fault magnitude–frequency relationships with uncertainties from a combinatorial optimization method that assigns individual earthquakes from a regional catalog to the different faults. Our model used a magnitude versus area relationship from Shaw (2023). His relationship was published with an error, M=f(1/√A)⁠, instead of M=f(1/A) (Shaw, 2025). Here, we recalculate the magnitude–frequency relationship with uncertainties using the Shaw (2025) corrected formula. The remaining parameters of the model, the model itself, and the number of repeated optimization runs have not changed. Figures 1 and 2 show the corrected results and replace figures 3 and 4 in the original article.

The Seismic Record↗
USGS1997

Dynamic deformations of shallow sediments in the Valley of Mexico, Part II: Single-station estimates

We develop simple relations to estimate dynamic displacement gradients (and hence the strains and rotations) during earthquakes in the lake-bed zone of the Valley of Mexico, where the presence of low-velocity, high-water content clays in the uppermost layers cause dramatic amplification of seismic waves and large strains. The study uses results from a companion article (Bodin et al. , 1997) in which the data from an array at Roma, a lake-bed site, were analyzed to obtain displacement gradients. In this article, we find that the deformations at other lake-bed sites may differ from those at Roma by a factor of 2 to 3. More accurate estimates of the dominant components of the deformation at an individual instrumented lake-bed site may be obtained from the maximum horizontal velocity and displacement, ν max and u max , at the surface. The maximum surface strain ɛ max is related to ν max by ɛ max = ν max / C , with C ∼ 0.6 km/sec. From the analysis of data from sites equipped with surface and borehole sensors, we find that the vertical gradient of peak horizontal displacement (Δ u max /Δ z ) computed from sensors at 0 and 30 m equals ( u max ) z=0 /Δ z , Δ z = 30 m, within a factor of 1.5. This is the largest gradient component, and the latter simple relation permits its estimation from surface records alone. The observed profiles of u max versus depth suggest a larger gradient in some depth range of 10 to 20 m, in agreement with synthetic calculations presented in Bodin et al. (1997).

Valley of Mexico↗
USGS1997

One minute after: Strong-motion map, effective epicenter, and effective magnitude

This article reports the recent progress on real-time seismic monitoring in Taiwan, particularly the real-time strong-motion monitoring by the Taiwan Central Weather Bureau's telemetered seismic network ( CWBSN ), which is presently aiming at rapid reporting immediately after a large earthquake occurrence. If rapid reporting can be achieved before the arrival of the strong shaking, earthquake early warning will become possible. CWBSN has achieved the generation of the intensity map, epicenter, and magnitude within 1 min of the occurrence of a large earthquake. Both rapid reporting and early warning are principally applied to large ( M ≫ 5) events; the requirement of on-scale waveform recording prompted CWBSN in 1995 to integrate strong-motion sensors (e.g., force-balance accelerometers) into its telemetered seismic monitoring system. Time-domain recursive processing is applied to the multi-channel incoming seismic signals by a group of networked personal computers to generate the intensity map. From the isoseismal contours, an effective epicenter is immediately identified that resides in the middle of the largest (usually the 100-gal) contour curve of the intensity map. An effective magnitude is also defined that can be derived immediately from the surface area covered by the largest (usually the 100-gal) contour curve. For a large event with a finite rupture surface, the epicenter and magnitude so derived are more adequate estimates of the source location and of the strength of destruction. The effective epicenter gives the center of the damage area; it stands in contrast with the conventional epicenter location, which only gives the initial point of rupture nucleation. The effective magnitude reflects more closely the earthquake damage potential, instead of the classical magnitude definition that emphasizes the total energy release. The CWBSN has achieved in obtaining the above crucial source information well within 1 min. This time can further be reduced to better than 30 sec, as illustrated by the example in this article, showing that earthquake early warning is indeed an achievable goal. The rapid reporting and early warning information is electronically transmitted to users to allow rapid response actions, with or without further human intervention.

Bulletin of the Seismological Society of America↗
USGS2012

The crowbar chronicles and other tales

The analysis of historical earthquakes often relies heavily on archival accounts describing the effects of shaking on structures and people. Newspaper articles are among the most common, useful, and easily found sources of information. Dramatic earthquake effects are almost certain to have made the news during historic times; the challenge for modern seismologists is not to be overly swayed by articles that focus on the most dramatic rather than the representative effects in a region. At the other end of the spectrum, rarely does a historical newspaper explicitly note that an earthquake was not felt in a certain area: it is not news when nothing happens. When earthquake effects are subtle, the vexing question is often, did they go unreported entirely?

Seismological Research Letters↗
USGS2020

The ODD protocol for describing agent-based and other simulation models: A second update to improve clarity, replication, and structural realism

The Overview, Design concepts and Details (ODD) protocol for describing Individual- and Agent-Based Models (ABMs) is now widely accepted and used to document such models in journal articles. As a standardized document for providing a consistent, logical and readable account of the structure and dynamics of ABMs, some research groups also find it useful as a workflow for model design. Even so, there are still limitations to ODD that obstruct its more widespread adoption. Such limitations are discussed and addressed in this paper: the limited availability of guidance on how to use ODD; the length of ODD documents; limitations of ODD for highly complex models; lack of sufficient details of many ODDs to enable reimplementation without access to the model code; and the lack of provision for sections in the document structure covering model design rationale, the model’s underlying narrative, and the means by which the model’s fitness for purpose is evaluated. We document the steps we have taken to provide better guidance on: structuring complex ODDs and an ODD summary for inclusion in a journal article (with full details in supplementary material; Table 1); using ODD to point readers to relevant sections of the model code; update the document structure to include sections on model rationale and evaluation. We also further advocate the need for standard descriptions of simulation experiments and argue that ODD can in principle be used for any type of simulation model. Thereby ODD would provide a lingua franca for simulation modelling.

Journal of Artificial Societies and Social Simulat↗
USGS2021

The green mole, Astromycter prasinatus T. M. Harris, 1825 (Mammalia: Eulipotyphla: Talpidae): An origin story

Thaddeus William Harris described the green mole of Maine, Condylura prasinata (Mammalia: Eulipotyphla: Talpidae), in the July 1825 issue of the Boston Journal of Philosophy and the Arts , and this was considered the original description of the species throughout most of the nineteenth century. In the early twentieth century, taxonomists began instead to cite an earlier notice in the June 1825 issue of the American Journal of Science and Arts . This short article also described the species, but also established a separate genus for it, Astromycter , despite Harris’s indications elsewhere that the species was congeneric with the star-nosed mole, Condylura cristata (Linnaeus, 1758). Moreover, the American Journal of Science and Arts article cited as its source the “ Machias Star ”, indicating the possibility of an even earlier description of the animal. With Astromycter prasinata in synonymy with C. cristata for over a century, little effort has been exerted to determine whether earlier source materials exist or why, within two months, the green mole was allocated to two different genera by its describer. The question is taxonomically relevant today because C. prasinata predates C. cristata nigra ( Smith, 1940), as an available name for north-eastern populations of star-nosed moles. If subspecies of C. cristata are to be recognized, the north-eastern subspecies should correctly bear the name C. cristata prasinata . In fact, authority for both genus- and species-group names for the green mole have been misattributed since 1825. The descriptions of C. prasinata by Thaddeus William Harris in the Boston Journal of Philosophy and the Arts and American Journal of Science and Arts were preceded by at least three published descriptions of A. prasinatus by Thaddeus Mason Harris, his father.

Archives of Natural History↗
USGS2025

Exploring the news media and scientific conversations around water quality in a water-rich basin of the United States

Community concerns about water availability vary depending on local economic, regulatory, environmental, and ecological considerations. In water-rich basins, water quality is often the focus of community concerns. As such, understanding community priorities in the context of water quality is crucial for informing scientists working in water-rich basins. In this work, we compiled over 6,500 local news articles (public discourse) and 190 scientific abstracts (scientific discourse) related to water-quality issues in the water-rich Illinois River Basin (ILRB) published between 2018 and 2022. We applied a Structural Topic Model (STM) to identify key water-quality topics within both datasets and explore the variability of newspaper topics geographically across the basin. Prevalent topics in both the public (local news articles) and scientific (abstracts) discourses were agriculture, drinking water quality, PFAS (per- and polyfluoroalkyl substances), and river ecosystem/fish. Topics exclusive to public discourse included water infrastructure, community development, and public water supply, while the scientific discourse focused more heavily on a wider range of agricultural issues. Furthermore, the public discourse varied geographically across the basin. Some topics are correlated with land use or urban/rural divides within the basin, and the frequency of many topics clearly varied across state (political) boundaries. Understanding and quantifying public and scientific discourses related to water-quality are important for scientists and water managers working in the basin to improve communication of critical science to the public.

Illinois, Indiana, Michigan, Wisconsin↗
USGS2025

Agronomic practices vs. natural soil factors: Influences on nitrous oxide emissions from corn and soybean fields.

Nitrous oxide (N 2 O), a potent greenhouse gas (GHG) and major contributor to climate change, is primarily released through agricultural activities. To better understand and quantify how land management practices, local climate conditions, and soil physicochemical properties affect these agricultural N 2 O emissions, we conducted a review of the peer-reviewed literature on N 2 O emission from corn [ Zea mays L.] and soybean [ Glycine max (L.) Merr.] fields. We evaluated the seasonal, cumulative effects of three nitrogen fertilizer rates—no fertilizer (0), low (<188 kg N ha −1 ), and high (188–400 kg N ha −1 )—tillage practices, local climate (precipitation and temperature), soil texture, and soil pH on soil N 2 O emissions. This meta-analysis included 77 articles for corn and 22 articles for soybean fields. Average N 2 O emissions during the corn rotation were 2.34 and 2.45 kg N 2 O-N ha −1 season −1 under low and high N fertilizer rates, respectively, and were both substantially ( p < 0.0001) greater than those of non-fertilized corn fields (0.91 kg N 2 O-N ha −1 season −1 ). Non-fertilized soybean fields showed seasonal N 2 O emissions of 0.74 kg N 2 O-N ha −1 , while low fertilizer application triggered a sharp increase (1.87 kg N 2 O-N ha −1 ) in N 2 O emissions by roughly 2.5 times ( p < 0.028). Increased temperature did not significantly ( p > 0.05) affect the emission of N 2 O from fertilized or non-fertilized corn fields. Regardless of fertilization and tillage practices, our analysis, including Principal Component Analysis, revealed that in corn fields, precipitation and soil pH are the dominant factors influencing soil N 2 O emissions. This study uniquely quantifies the influence of climate–soil factors, such as precipitation and soil pH, alongside agronomic practices, on N 2 O emissions, offering new insights beyond previous reviews focused primarily on fertilizer rates or tillage effects.

Agronomy↗
USGS2015

Evaluation of airborne lidar elevation surfaces for propagation of coastal inundation: the importance of hydrologic connectivity

Detailed information about coastal inundation is vital to understanding dynamic and populated areas that are impacted by storm surge and flooding. To understand these natural hazard risks, lidar elevation surfaces are frequently used to model inundation in coastal areas. A single-value surface method is sometimes used to inundate areas in lidar elevation surfaces that are below a specified elevation value. However, such an approach does not take into consideration hydrologic connectivity between elevation grids cells resulting in inland areas that should be hydrologically connected to the ocean, but are not. Because inland areas that should drain to the ocean are hydrologically disconnected by raised features in a lidar elevation surface, simply raising the water level to propagate coastal inundation will lead to inundation uncertainties. We took advantage of this problem to identify hydrologically disconnected inland areas to point out that they should be considered for coastal inundation, and that a lidar-based hydrologic surface should be developed with hydrologic connectivity prior to inundation analysis. The process of achieving hydrologic connectivity with hydrologic-enforcement is not new, however, the application of hydrologically-enforced lidar elevation surfaces for improved coastal inundation mapping as approached in this research is innovative. In this article, we propagated a high-resolution lidar elevation surface in coastal Staten Island, New York to demonstrate that inland areas lacking hydrologic connectivity to the ocean could potentially be included in inundation delineations. For inland areas that were hydrologically disconnected, we evaluated if drainage to the ocean was evident, and calculated an area exceeding 11 ha (~0.11 km 2 ) that could be considered in inundation delineations. We also assessed land cover for each inland area to determine the type of physical surfaces that would be potentially impacted if the inland areas were considered as part of a coastal inundation. A visual analysis indicated that developed, medium intensity and palustrine forested wetland land cover types would be impacted for those locations. This article demonstrates that hydrologic connectivity is an important factor to consider when inundating a lidar elevation surface. This information is needed for inundation monitoring and management in sensitive coastal regions.

Remote Sensing↗
USGS2013

Ecology of potential West Nile virus vectors in southeastern Louisiana: enzootic transmission in the relative absence of Culex quinquefasciatus

A study of West Nile virus (WNV) ecology was conducted in St. Tammany Parish, Louisiana, from 2002 to 2004. Mosquitoes were collected weekly throughout the year using Centers for Disease Control and Prevention (CDC) light traps placed at 1.5 and 6 m above the ground and gravid traps. A total of 379,466 mosquitoes was collected. WNV was identified in 32 pools of mosquitoes comprising four species; 23 positive pools were from Culex nigripalpus collected during 2003. Significantly more positive pools were obtained from Cx. nigripalpus collected in traps placed at 6 m than 1.5 m that year, but abundance did not differ by trap height. In contrast, Cx. nigripalpus abundance was significantly greater in traps placed at 6 m in 2002 and 2004. Annual temporal variation in Cx. nigripalpus peak seasonal abundance has important implications for WNV transmission in Louisiana. One WNV-positive pool, from Cx. erraticus, was collected during the winter of 2004, showing year-round transmission. The potential roles of additional mosquito species in WNV transmission in southeastern Louisiana are discussed. Disclaimer: The opinions expressed in this article are the opinions of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. This article has been peer reviewed and approved for publication consistent with U.S. Geological Survey Fundamental Science Practices (http//pubs.usgs.gov/circ/1367/). Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Louisiana↗
USGS2022

Long-term ocean observing for international capacity development around tsunami early warning

The 2004 magnitude (M) 9.1 Sumatra-Andaman Islands earthquake in the Indian Ocean triggered the deadliest tsunami ever, killing more than 230,000 people. In response, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) established three additional Intergovernmental Coordination Groups (ICGs) for the Tsunami and Other Coastal Hazards Early Warning System: for the Caribbean and Adjacent Regions (ICG/CARIBE-EWS), for the Indian Ocean, and for the Northeastern Atlantic, Mediterranean, and Connected Seas. Along with the ICG for the Pacific Ocean, which was established in 1965, one of the goals of the new ICGs was to improve earthquake and tsunami monitoring and early warning. This need was further demonstrated by the 2011 Great East Japan (Tōhoku-oki) earthquake and tsunami, which killed more than 20,000 people, and other destructive tsunamis that occurred in the Solomon Islands, Samoa, Tonga, Chile, Indonesia, and Peru. In response to the call to action by the UN Decade of Ocean Science for Sustainable Development (2021–2030), as well as the desired safe ocean outcome (von Hillebrandt-Andrade et al., 2021), the Intergovernmental Oceanographic Commission (IOC) of UNESCO approved the Ocean Decade Tsunami Programme in June 2021. One of its goals is to develop the capability to issue actionable alerts for tsunamis from all sources with minimum uncertainty within 10 minutes (Angove et al., 2019). While laudable, this goal presents complexities. Currently, warning depends on quick detection as well as the location and initial magnitude estimates of an earthquake that may generate a tsunami. Other factors that affect tsunamis, such as the faulting mechanism (how the faults slide past each other) and areal extent of the earthquake, currently take at least 20–30 minutes to forecast and are still subject to large uncertainties. Hence, agencies charged with tsunami early warning need to broadcast public alerts within minutes after an earthquake occurs but may struggle to meet this 10-minute goal without further technological advances, some of which are outlined in this article. To reduce loss of life through adequate tsunami warning requires global ocean-based seismic, sea level, and geodetic initiatives to detect high-impact earthquakes and tsunamis, combined with sufficient communication and education so that people know how to respond when they receive alerts and warnings. The United Nations International Strategy for Disaster Reduction defines an early warning system as “a set of capacities needed to generate and disseminate timely and meaningful warning information to enable individuals, communities, and organizations threatened by a hazard to prepare and to act appropriately and in sufficient time to reduce the possibility of harm or loss” (UNISDR, 2012). In short, a successful early warning system requires technology coupled with human factors (Kelman and Glantz, 2014). In this article, we explore case studies from Japan and Canada, where scientists are leading the way in incorporating ocean observing capabilities in their early warning systems. We also explore advancements and challenges in the Caribbean, an area with a complex tectonic environment that would benefit greatly from increased global ocean observing capabilities. We also explore physical and social science interventions necessary to reduce loss of life.

Oceanography↗
USGS2017

Regime shifts and panarchies in regional scale social-ecological water systems

In this article we summarize histories of nonlinear, complex interactions among societal, legal, and ecosystem dynamics in six North American water basins, as they respond to changing climate. These case studies were chosen to explore the conditions for emergence of adaptive governance in heavily regulated and developed social-ecological systems nested within a hierarchical governmental system. We summarize resilience assessments conducted in each system to provide a synthesis and reference by the other articles in this special feature. We also present a general framework used to evaluate the interactions between society and ecosystem regimes and the governance regimes chosen to mediate those interactions. The case studies show different ways that adaptive governance may be triggered, facilitated, or constrained by ecological and/or legal processes. The resilience assessments indicate that complex interactions among the governance and ecosystem components of these systems can produce different trajectories, which include patterns of (a) development and stabilization, (b) cycles of crisis and recovery, which includes lurches in adaptation and learning, and (3) periods of innovation, novelty, and transformation. Exploration of cross scale (Panarchy) interactions among levels and sectors of government and society illustrate that they may constrain development trajectories, but may also provide stability during crisis or innovation at smaller scales; create crises, but may also facilitate recovery; and constrain system transformation, but may also provide windows of opportunity in which transformation, and the resources to accomplish it, may occur. The framework is the starting point for our exploration of how law might play a role in enhancing the capacity of social-ecological systems to adapt to climate change.

Ecology and Society↗
USGS1936

Low production may not mean depletion

Five feeding tests were conducted at the Patuxent Research Refuge, Bowie, Maryland, to determine the value or dwarf and smooth sumac fruits as the sole diet of quail, as well as a supplement to other feedstuffs.....When whole sumac fruits were force-fed quail, either alone or in combination with millet seed, many of the sumac seed were defecated undigested, whereas the millet seed was digested. Likewise, many sumac seed passed through the quail undigested when sumac fruit was fed ad libitum subsequent to a fasting period.....The quail did not relish sumac fruit as the sole article of diet. They lost weight nearly as rapidly on the fruit, ground or whole, 'the ground seed, or the pulp as they did when not given any food....Quail maintained their weight for 14 weeks during the late fall and winter in outdoor pens on a diet containing 50 per cent sumac fruit-pulp and other feedstuffs of high feeding value. A severe neck molt, however, occurred during the ninth week.....Quail lost weight rapidly on a diet containing 75 per cent sumac even though kept away from adverse weather conditions. A severe neck molt took place during the first week of this high-sumac diet. Heavy mortality occurred during the third and fourth weeks....Where the birds had a choice of many feedstuffs, they made sumac fruit 2 to 4 per cent of their diet....Therefore, it must be concluded, that even though sumac fruit is eaten by quail, and as a small percentage of the diet it may have a definite nutritional value, nevertheless as the sole or primary article of diet, it cannot be expected to maintain quail through a critical period in the winter.

The Fisherman↗
USGS1995

Partnerships and opportunities: The archival management of geographic information systems

This article provides an overview of geographic information systems (GISs) technology and applications. It discusses its implications for archives, including a review of the existing literature. Finally, the article recommends a strategy for managing such systems based on the study of an environmental GIS application in a federal research center and on the vision recently expressed by David Bearman and Margaret Hedstrom. A multi-staged approach to the archival management of GISs is recommended and new partnerships are suggested to aid archivists in the future management of these systems.

Archival Issues↗
USGS1993

Restoration ecology: longterm evaluation as an essential feature of rehabilitation

In its brief existence as a recognized scientific discipline, restoration ecology has focused almost exclusively on terrestrial and wetland habitat. As a consequence, aquatic restoration and rehabilitation, an important component of restoration ecology is a relatively new discipline. This article examines the ecosystem approach to rehabilitation of the Great Lakes Basin and proposes that waterfront redevlopment and terrestrial and wetland habitat restoration should be accompanied by aquatic habitat restoration. Furthermore, aquatic habitat restoration must include rehabilitation of hard-bottom substrates and structures as well as pollution cleanup and management of soft sediments. Lastly, the article suggests that longterm evaluation is indispensable for aquatic habitat restoration and rehabiliation to be truly successful in the Great Lakes region. Only through longterm evaluation can we determine whether habitat restoration goals have been met at specific sites and transfer successful lessons learned at other locations.

Buffalo Environmental Law Journal↗
USGS2001

We still need Smokey Bear!

It was gratifying to see articles in recent issues of Fire Management Today clarifying the role of Smokey Bear in wildland fire management strategies (Baily 1999; Brown 1999). These articles clearly spelled out Smokey’s importance in reducing unplanned human-ignited wildland fires and rightly criticized attempts to detract from Smokey’s campaign (Williams 1995; see also Vogl 1973).

Fire Management Today↗