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Initial dispersal (1986-1987) of the invasive foraminifera Trochammina hadai Uchio in San Francisco Bay, California, USA

A time series of three closely-spaced data sets are used to track the early expansion of the invasive Japanese benthic foraminifera Trochammina hadai in the southern portion of San Francisco Bay known as South Bay. The species initially appeared in 1983, comprising only 1.5% of the assemblage in one of four samples that were dominated by the native species Ammonia tepida and Cribroelphidium excava

Authors
Mary McGann

The occurrence of the invasive foraminifera Trochammina hadai Uchio in Flamengo Inlet, Ubatuba, São Paulo State, Brazil

The agglutinated foraminifera Trochammina hadai Uchio (1962), a dominant species in Japan, first appeared as an invasive species in San Francisco Bay, US, in 1983. Trochammina hadai's first appearance in the Brazilian coastal waters of Flamengo Inlet, Ubatuba, Sao Paulo State, is recorded nearly three decades later, in two of thirty-four sediment samples collected in the western portion known as "
Authors
Patricia P. B. Eichler, Mary McGann, Andre R. Rodrigues, Alison Mendonca, Audrey Amorim, Carla Bonetti, Cristiane Cordeito de Farias, Silvia H. Mello e Sousa, Helenice Vital, Moab Praxedes Gomes

Digital Shoreline Analysis System (DSAS) version 5.0 user guide

OverviewThe Digital Shoreline Analysis System (DSAS) is a freely available software application that works within the Esri Geographic Information System (ArcGIS) software. DSAS computes rate-of-change statistics for a time series of shoreline vector data. DSAS version 5.0 (v5.0) was released in December 2018 and has been tested for compatibility with ArcGIS versions 10.4 and 10.5. It is supported
Authors
Emily A. Himmelstoss, Rachel E. Henderson, Meredith G. Kratzmann, Amy S. Farris

On the potential duration of the aftershock sequence of the 2018 Anchorage earthquake

Currently, an aftershock sequence is ongoing in Alaska after the magnitude 7.0 Anchorage earthquake of November 30, 2018. Using two scenarios, determined with observations as of December 14, 2018, this report estimates that it will take between 2.5 years and 3 decades before the rate of aftershocks decays to the rate of earthquakes that were occurring in this area before the magnitude 7.0 mainshoc
Authors
Andrew J. Michael

Long-term soil-water tension measurements in semi-arid environments: A method for automated tensiometer refilling

Tensiometer-equipped data acquisition systems measure and record positive and negative soil-water pressures. These data contribute to studies in hillslope hydrology, including analyses of rainfall runoff, near-surface hydrologic response, and slope stability. However, the unique ability of a tensiometer to rapidly and accurately measure pre- and post-saturation subsurface pressures requires mainte
Authors
Joel B. Smith, Jason W. Kean

Earthquakes induced by hydraulic fracturing are pervasive in Oklahoma

Wastewater disposal is generally accepted to be the primary cause of the increased seismicity rate in Oklahoma within the past decade, but no statewide analysis has investigated the contribution of hydraulic fracturing (HF) to the observed seismicity or the seismic hazard. Utilizing an enhanced seismicity catalog generated with multi‐station template matching from 2010‐2016 and all available hydra
Authors
Robert J. Skoumal, Rosamiel Ries, Michael R. Brudzinski, Andrew J. Barbour, Brian S. Currie

Microseismic events associated with the Oroville Dam spillway

On 14 February 2017, two small (equivalent MD 0.8 and 1.0) seismic events occurred in proximity to the Oroville Dam in the Sierra Nevada foothills, California. To examine possible causal relationships between these events and reservoir operations, including the spillway failure starting prior to these events, we applied a new optimized template matching approach to seismic data between May 1993 -
Authors
Robert J. Skoumal, Phillip B. Dawson, Stephen H. Hickman, J. Ole Kaven

Ground motions from induced earthquakes in Oklahoma and Kansas

Improved predictions of earthquake ground motions are critical to advancing seismic hazard analyses and earthquake response. The high seismicity rate from 2009 to 2016 in Oklahoma and Kansas provides an extensive data set for examining the ground motions from these events. We evaluate the ability of three suites of ground‐motion prediction equations (GMPEs)—appropriate for modeling tectonic earthq
Authors
Morgan P. Moschetti, Eric M. Thompson, Peter M. Powers, Susan M. Hoover, Daniel E. McNamara

Salt marsh ecosystem restructuring enhances elevation resilience and carbon storage during accelerating relative sea-level rise

Salt marshes respond to sea-level rise through a series of complex and dynamic bio-physical feedbacks. In this study, we found that sea-level rise triggered salt marsh habitat restructuring, with the associated vegetation changes enhancing salt marsh elevation resilience. A continuous record of marsh elevation relative to sea level that includes reconstruction of high-resolution, sub-decadal, mars
Authors
Meagan Gonneea Eagle, Christopher V. Maio, Kevin D. Kroeger, Andrea D. Hawkes, Jordan Mora, Richard Sullivan, Stephanie Madsen, Richard M. Buzard, Niamh Cahill, Jeffrey P. Donnelly

On the contribution of waves to total coastal water level changes in the context of sea level rise: a response to Melet, et al. (2018)

Response to Melet, A., Meyssignac, B., Almar, R. & Le Cozannet, G. Under-estimated wave contribution to coastal sea-level rise. Nat. Clim. Change 8, 234–239 (2018). In a recent paper, Melet et al.1 claim that the contribution of wind-waves to coastal sea-level rise has been under-estimated. Although we agree with the overall premise that coastal wind-wave dynamics are important when assessing the
Authors
Jerome Aucan, Ron Hoeke, Curt D. Storlazzi, Justin Stopa, Moritz Wandres, Ryan J. Lowe

Hydrologic controls of methane dynamics in karst subterranean estuaries

Karst subterranean estuaries (KSEs) extend into carbonate platforms along 12% of all coastlines. A recent study has shown that microbial methane (CH4) consumption is an important component of the carbon cycle and food web dynamics within flooded caves that permeate KSEs. In this study, we obtained high‐resolution (~2.5‐day) temporal records of dissolved methane concentrations and its stable isotop
Authors
David Brankovits, John W. Pohlman, Neil K. Ganju, T.M. Iliffe, N. Lowell, E. Roth, S.P. Sylva, J.A. Emmert, L. L. Lapham

Seismology with dark data: Image-based processing of analog records using machine learning for the rangely earthquake control experiment

Before the digital era, seismograms were recorded in analog form and read manually by analysts. The digital era represents only about 25% of the total time span of instrumental seismology. Analog data provide important constraints on earthquake processes over the long term, and in some cases are the only data available. The media on which analog data are recorded degrades with time and there is an
Authors
Kaiwen Wang, William L. Ellsworth, Gregory C. Beroza, Gordon Williams, Miao Zhang, Dustin Schroeder, Justin L. Rubinstein