Geology topics

Joseph E Thomas

Publications and source records attributed to Joseph E Thomas.

4 recordsLinked to original sources

USGS2025

Grand Canyon River Alert System—Implementing an emergency alert system for wilderness recreation

The Grand Canyon River Alert System (GCRAS) provides government-issued emergency alerts to wilderness recreationalists in the Grand Canyon, who are often outside the bounds of cellular signal reception. GCRAS is a collaboration between the U.S. Geological Survey (Grand Canyon Monitoring and Research Center), National Weather Service, Coconino County Emergency Management, and National Park Service. Technological advances in satellite communications have improved satellite signal availability in remote areas and increased the reliability of satellite communications using personal devices such as commercially available satellite messaging devices. These advancements have presented an opportunity to create a novel emergency alert system designed primarily for backcountry visitors to provide improved communications for periods of increased risk and potentially dangerous situations in the backcountry. GCRAS is designed specifically for the distinctive needs of satellite messaging devices and features reduced character count messages, short-code signup capability, and the ability to unsubscribe at any time. After a positive test of the system in March 2024, the system went live to the public and has been used more than two dozen times in 2024 to inform boaters and hikers of hazards (such as debris flows and flash floods) in the Grand Canyon. Satellite signal availability and device response time varies based on location and service provider, but initial testing showed messages arriving within 2–10 minutes. Although GCRAS was developed specifically for the Grand Canyon, the GCRAS framework could be applied to other wilderness areas. It can be used by emergency management authorities, land-management agencies, search and rescue units, and those concerned with public safety to help increase communication with people visiting or living in areas that are outside the signal of more traditional emergency-notification methods, such as cellular, wireless emergency alerts, and sirens.

Arizona↗

USGS2024

Grand Canyon River Alerts: An emergency alert system designed for satellite texting devices

The Grand Canyon River Alert system is now live! The U.S. Geological Survey, Grand Canyon Monitoring and Research Center (GCMRC), in collaboration with Coconino County Emergency Management (CCEM), the National Weather Service (NWS) and the National Park Service (NPS), have developed and implemented a framework for sending emergency alerts to boaters and hikers in Grand Canyon. The system is specifically designed to send alerts to satellite texting devices, such those sold by Garmin and SPOT, and is a first of its kind in the nation. Alert messaging will be provided by NPS, NWS, or the Bureau of Reclamation depending on the nature of the incident. CCEM will disseminate alert messaging to devices subscribed to the Grand Canyon River Alerts list. Boating hazards, missing persons, critical dam related events, and extreme weather and flash flood hazards will be included in alert messaging.

Arizona↗

USGS2024

Estimating migration timing and abundance in partial migratory systems by integrating continuous antenna detections with physical captures

Many populations migrate between two different habitats (e.g. wintering/foraging to breeding area, mainstem–tributary, river–lake, river–ocean, river–side channel) as part of their life history. Detection technologies, such as passive integrated transponder (PIT) antennas or sonic receivers, can be placed at boundaries between habitats (e.g. near the confluence of rivers) to detect migratory movements of marked animals. Often, these detection systems have high detection probabilities and detect many individuals but are limited in their ability to make inferences about abundance because only marked individuals can be detected. Here, we introduce a mark–recapture modelling approach that uses detections from a double-array PIT antenna system to imply movement directionality from arrays and estimate migration timing. Additionally, when combined with physical captures, the model can be used to estimate abundances for both migratory and non-migratory groups and help quantify partial migration. We first test our approach using simulation, and results indicate our approach displayed negligible bias for total abundance (less than ±1%) and slight biases for state-specific abundance estimates (±1%–6%). We fit our model to array detections and physical captures of three native fishes (humpback chub [ Gila cypha ], flannelmouth sucker [ Catostomus latipinnis ] and bluehead sucker [ Catostomus discobolus ]) in the Little Colorado River (LCR) in Grand Canyon, AZ, a system that exhibits partial migration (i.e. includes residents and migrants). Abundance estimates from our model confirm that, for all three species, migratory individuals are much more numerous than residents. There was little difference in movement timing between 2021 (a year without preceding winter/spring floods) and 2022 (a year with a small flood occurring in early April). In both years, flannelmouth sucker arrived in mid-March whereas humpback chub and bluehead sucker arrivals occurred early- to mid-April. With humpback chub and flannelmouth sucker, movement timing was influenced by body size so that large individuals were more likely to arrive early compared to smaller individuals. With more years of data, this model framework could be used to evaluate ecological questions pertaining to flow cues and movement timing or intensity, relative trends in migrants versus residents and ecological drivers of skipped spawning.

Journal of Animal Ecology↗

USGS2024

U.S. Geological Survey Grand Canyon Monitoring and Research Center: Proceedings of the fiscal year 2023 annual reporting meeting to the Glen Canyon Dam Adaptive Management Program

This proceedings is prepared for the USBR and Glen Canyon Dam Adaptive Management Program (GCDAMP) to account for work conducted and products delivered in FY 2023 by SBSC's Grand Canyon Monitoring and Research Center (GCMRC) and to inform the Technical Work Group of science conducted by GCMRC and its cooperators in support of the GCDAMP. It includes a summary of accomplishments, modifications to work plans, and results related to projects included in GCMRC’s FY 2021-23 Triennial Work Plan. This work was done to support the 11 resource goals identified in the Glen Canyon Dam Long-Term Experimental and Management Plan (LTEMP) Environmental Impact Statement and Record of Decision.

Arizona, Nevada, Utah↗