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United States · Complex volcano

Three Sisters

Type
Complex volcano
Elevation
3159m
Last eruption
439
Three Sisters
Photo: USGS photo by Lyn Topinka · Public domain · Wikimedia Commons
Type
Complex volcano
Country
United States
Region
North America / High Cascades Volcanic Arc
Elevation
3159m
Coordinates
44.133, -121.767
Last eruption
439
Tectonic setting
Subduction zone / Continental crust (> 25 km)
Landform
Composite
Major rock type
Andesite / Basaltic andesite

Geological summary

The north-south-trending Three Sisters volcano group dominates the landscape of the Central Oregon Cascades.

Excerpt from the Global Volcanism Program, Smithsonian Institution · Read the full summary on GVP →

From Wikipedia

The Three Sisters are a trio of closely spaced volcanic peaks in the U.S. state of Oregon. Named North, Middle, and South, they are part of the Cascade Volcanic Arc, a segment of the Cascade Range in western North America extending from southern British Columbia through Washington and Oregon to Northern California. Each over 10,000 feet in elevation, they are the third-, fourth- and fifth-highest peaks in Oregon.

Wikipedia · CC BY-SA · Read full article →

Eruption history

6 recordedGlossary

Record summary

Confirmed eruptions
6
Uncertain eruptions
0
Span of confirmed record
7350 BCE (±2700 yrs) – 439
Largest confirmed eruption
VEI 4 (350 BCE)
Confirmed eruptions since 1900
0
Summary (VEI over time)
Click a bar to see individual eruptions · Use arrow keys to move between bars, Enter to open
7350 BCE~7090 BCE · 1 eruptions · max VEI 2859 BCE~600 BCE · 1 eruptions · max VEI 2600 BCE~340 BCE · 1 eruptions · max VEI 480 BCE~179 · 2 eruptions · max VEI 3179~439 · 1 eruptions · max VEI 27350 BCE5533 BCE3455 BCE1638 BCE179

Detailed timeline

  1. 439 (±108 yrs)VEI 2Geological estimate
    439 – end unknown
    NW of North Sister (Collier Cone)
  2. 40 (±202 yrs)VEI 2Geological estimate
    40 – end unknown
    NW of North Sister (Four-in-One Cone)
  3. 50 BCEVEI 3Geological estimate
    50 BCE – end unknown
    N & S flanks of South Sister (Devils Hill)
  4. 350 BCEVEI 4Geological estimate
    350 BCE – end unknown
    SW flank of South Sister (Rock Mesa)
  5. 800 BCEVEI 2Geological estimate
    800 BCE – end unknown
    North of North Sister (Yapoah Cone)
  6. 7350 BCE (±2700 yrs)VEI 2Geological estimate
    7350 BCE – end unknown
    WNW of North Sister (Sims Butte)

Nearby volcanoes

External links

⚠ For reference only. Not for emergency response.