A combined paleoflood and flood hydroclimatology study on the Snake River in Idaho and Oregon suggests a link between floods and patters of geopotential height anomalies over the North Pacific Ocean. Examination of the paleoflood record in two 4-m (12 ft) tall terraces along the Hells Canyon reach of the Snake River in Idaho and Oregon shows evidence of at least twenty-two late-Holocene extreme floods that occurred approximately 5,000 years. The ages of paleoflood deposits at these sites fall into two time periods, from 5130 ± 40 to 1960 ± 40 yr BP and from 320 ± 40 yr BP to post-AD 1950 with one flood deposit in between. The significant reduction in the number of deposits between these two time ranges suggests a hiatus in floods that were able to leave slackwater deposits above the 3-m (9 ft) height.
Examination of a 52-year record of recent flood-climate variability shows a consistent pattern of northeast trending negative geopotential height anomalies over the northern Pacific Ocean prior to extreme winter floods on the Snake River. The pattern of northeast-trending negative geopotential height anomalies in winter may be responsible for the floods that generated the 5,000-year long paleoflood record on the Snake River.
Since the Snake River drains a climatically diverse region, understanding the nature of past floods on the river enhances a larger effort to understand the links between flood hydroclimatology and flood frequency in the northwestern United States.
","abstract_html":"<p>A combined paleoflood and flood hydroclimatology study on the Snake River in Idaho and Oregon suggests a link between floods and patters of geopotential height anomalies over the North Pacific Ocean. Examination of the paleoflood record in two 4-m (12 ft) tall terraces along the Hells Canyon reach of the Snake River in Idaho and Oregon shows evidence of at least twenty-two late-Holocene extreme floods that occurred approximately 5,000 years. The ages of paleoflood deposits at these sites fall into two time periods, from 5130 ± 40 to 1960 ± 40 yr BP and from 320 ± 40 yr BP to post-AD 1950 with one flood deposit in between. The significant reduction in the number of deposits between these two time ranges suggests a hiatus in floods that were able to leave slackwater deposits above the 3-m (9 ft) height.</p> <p>Examination of a 52-year record of recent flood-climate variability shows a consistent pattern of northeast trending negative geopotential height anomalies over the northern Pacific Ocean prior to extreme winter floods on the Snake River. The pattern of northeast-trending negative geopotential height anomalies in winter may be responsible for the floods that generated the 5,000-year long paleoflood record on the Snake River.</p> <p>Since the Snake River drains a climatically diverse region, understanding the nature of past floods on the river enhances a larger effort to understand the links between flood hydroclimatology and flood frequency in the northwestern United States.</p>","abstract_has_math":false,"creators":["Rhodes, Gwendolyn Bernitha"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":null,"degree_discipline":"Geological Sciences","degree_department":null,"school":null,"contributors":["Lisa L. Ely","Carey Gazis","James Hinthorne"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2001,"date_issued":"2001-01-01T08:00:00Z","date_published":"2001-01-01T08:00:00Z","updated_at":"2026-07-24T01:37:54Z","subjects":["floods","Snake River","Oregon","Idaho","hydroclimatology","Holocene","Geomorphology","Hydrology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.cwu.edu/etd/1473","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Lisa L. Ely","Carey Gazis","James Hinthorne"]},{"key":"dc:creator","label":"Author","values":["Rhodes, Gwendolyn Bernitha"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2020-12-22T08:00:00Z"]},{"key":"dc:type","label":"Dc Type","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geological Sciences"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["floods","Snake River","Oregon","Idaho","hydroclimatology","Holocene","Geomorphology","Hydrology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.cwu.edu/etd/1473"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A combined paleoflood and flood hydroclimatology study on the Snake River in Idaho and Oregon suggests a link between floods and patters of geopotential height anomalies over the North Pacific Ocean. Examination of the paleoflood record in two 4-m (12 ft) tall terraces along the Hells Canyon reach of the Snake River in Idaho and Oregon shows evidence of at least twenty-two late-Holocene extreme floods that occurred approximately 5,000 years. The ages of paleoflood deposits at these sites fall into two time periods, from 5130 ± 40 to 1960 ± 40 yr BP and from 320 ± 40 yr BP to post-AD 1950 with one flood deposit in between. The significant reduction in the number of deposits between these two time ranges suggests a hiatus in floods that were able to leave slackwater deposits above the 3-m (9 ft) height.
Examination of a 52-year record of recent flood-climate variability shows a consistent pattern of northeast trending negative geopotential height anomalies over the northern Pacific Ocean prior to extreme winter floods on the Snake River. The pattern of northeast-trending negative geopotential height anomalies in winter may be responsible for the floods that generated the 5,000-year long paleoflood record on the Snake River.
Since the Snake River drains a climatically diverse region, understanding the nature of past floods on the river enhances a larger effort to understand the links between flood hydroclimatology and flood frequency in the northwestern United States.
"]},{"key":"dc:title","label":"Title","values":["A small look at the big picture: linking geopotential height anomalies to paleofloods on the Snake River, Idaho and Oregon"]}]}],"canonical_facts":{"dc:contributor":["Lisa L. Ely","Carey Gazis","James Hinthorne"],"dc:creator":["Rhodes, Gwendolyn Bernitha"],"dc:date.available":["2020-12-22T08:00:00Z"],"dc:description.abstract":["A combined paleoflood and flood hydroclimatology study on the Snake River in Idaho and Oregon suggests a link between floods and patters of geopotential height anomalies over the North Pacific Ocean. Examination of the paleoflood record in two 4-m (12 ft) tall terraces along the Hells Canyon reach of the Snake River in Idaho and Oregon shows evidence of at least twenty-two late-Holocene extreme floods that occurred approximately 5,000 years. The ages of paleoflood deposits at these sites fall into two time periods, from 5130 ± 40 to 1960 ± 40 yr BP and from 320 ± 40 yr BP to post-AD 1950 with one flood deposit in between. The significant reduction in the number of deposits between these two time ranges suggests a hiatus in floods that were able to leave slackwater deposits above the 3-m (9 ft) height.
Examination of a 52-year record of recent flood-climate variability shows a consistent pattern of northeast trending negative geopotential height anomalies over the northern Pacific Ocean prior to extreme winter floods on the Snake River. The pattern of northeast-trending negative geopotential height anomalies in winter may be responsible for the floods that generated the 5,000-year long paleoflood record on the Snake River.
Since the Snake River drains a climatically diverse region, understanding the nature of past floods on the river enhances a larger effort to understand the links between flood hydroclimatology and flood frequency in the northwestern United States.
"],"dc:identifier":["https://digitalcommons.cwu.edu/etd/1473"],"dc:subject":["floods","Snake River","Oregon","Idaho","hydroclimatology","Holocene","Geomorphology","Hydrology"],"dc:title":["A small look at the big picture: linking geopotential height anomalies to paleofloods on the Snake River, Idaho and Oregon"],"dc:type":["Text"],"thesis:degree_discipline":["Geological Sciences"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T01:37:54Z"}