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Title

Cesium-137 Lake Sediment Depth Profiles and Inventories in Idaho’s Sawtooth Wilderness

Organization

Department: Nuclear Eng'g & Health Physics

University: Idaho State University College: Science & Engineering Department: Nuclear Eng'g & Health Physics 23

Document Attachments

Resource	Length	Width	Thickness
Paper	0	0	0

Specimen Elements

City

Pocatello

Coverage

Unknown to Unknown

Creator

Benjamin Bishop

Publisher

Idaho State University

Type

Thesis

Is Complete

No

Date Published

7/6/2018

Archive

digital

City: Pocatello

Degree

Master

Document Attachments

Abstracts

A total of 68 sediment cores from four freshwater alpine lakes in Idaho’s Sawtooth Wilderness were collected during the summer of 2017. The objectives of the study were to determine depth distributions of 137Cs in the cores using gamma spectrometry and estimate the sedimentation rates of the lakes from the identified geochronological peaks linked to nuclear fallout. Cesium-137 radioactivity above background was detected in all studied lakes. The maximum 137Cs concentrations measured in each lake’s sediment ranged from 74.0  6.09 to 255.3  7.48 Bq kg-1. Relationships between total 137Cs deposition and elevation, latitude, and pH were tested and found to be nonexistent, but lake flushing and geological location are suggested to be primary factors. Three of the lakes had 137Cs sediment depth distributions that resembled the deposition pattern of weapons testing as a function of time. Mean sedimentation rate estimates ranged from 0.08  0.29 to 0.12  0.05 cm y-1 and decreased with increasing altitude.