ZME Science
No Result
View All Result
ZME Science
No Result
View All Result
ZME Science

Home → Science → Geology

The Bulge is back: Three Sister volcano in Oregon triggers swelling but is unlikely to erupt

GPS equipment can track very subtle ground movements.

Mihai AndreibyMihai Andrei
February 2, 2022
in Geology, News
A A
Share on FacebookShare on TwitterSubmit to Reddit

Using satellite images and GPS instruments, geophysicists monitoring the Three Sister volcanoes have found a subtle but noticeable uplift around 3 miles (5 km) away from the South Sister volcano. While researchers are now keeping a closer eye on it, they say this type of uplift has happened before and there’s no need to worry.

Image credits: USGS.

The Three Sisters are closely spaced volcanic peaks in Oregon, USA. They stand over 10,000 feet (3,000 m) in elevation, being the 4th, 5th, and 6th highest peaks in Oregon, respectively. But researchers are more interested in their volcanic activity.

While the North and Middle sisters haven’t erupted in the past 14,000 years (and it’s considered unlikely that they will erupt again), the South Sister last erupted 2,000 years ago, and could easily do so again at some point in the not-very-distant future. In the 1990s, researchers detected tectonic uplift around this volcano, prompting the United States Geological Survey (USGS) to closely monitor the area.

The USGS is now tracking developments around the South Sister using GPS networks and satellite data. Radar satellites can highlight areas of uplifting (where the surface is bulging) or downwelling (where the surface is moving downwards). Then, ground-based GPS measurements are used for more precise measurements. Although the current uplifting isn’t as fast as the maximum rate observed in 1999-2000, it is “distinctly faster” than the normal rate of uplift, the USGS says.

Image credits: USGS.

The uplift is believed to be caused by pulses of magma accumulating under the volcano, some 4 miles (7 km) below the surface. While magma accumulation is associated with volcanic activity, eruptions are generally preceded by other detectable signs — most importantly, lots of small earthquakes, but also ground deformation and geochemical changes. There seems to be no sign of any of that around the Three Sisters.

All in all, this suggests that the volcano is still active, but there are no signs of an impending eruption. The volcano’s alert level and color code remain at Normal / Green.

How the USGS is tracking activity around the Three Sisters. Credit: USGS.

The Three Sisters volcanoes formed in the Pleistocene and belonged to a volcanic area that was very active from around 650,000 and about 250,000 years ago. The South Sister is the youngest and tallest of the three volcanoes, and unlike its sisters, it has an uneroded summit crater about 0.25 mi (0.40 km), which hosts a lake (called the Teardrop Pool).

RelatedPosts

Why Some People Never Get Lost — and Others Always Do
Little-known 2012 volcanic eruption was actually the largest in over a century, new data shows
Indonesian volcano erupted twice last Sunday
Using volcanoes to power liquid fuel production

An eruption from the South Sister would pose a significant threat to nearby life, with geologists estimating a proximal zone of danger extending from 1.2 to 6.2 miles (2-10 km) around the volcano summit. How flows would run down the sides of the volcano, threatening everything in its path, and the nearby city of bends would be covered by tephra some 2 inches (5 cm) thick.

The Teardrop Pool on South Sister is the highest lake in Oregon. Image via Wiki Commons.

Tags: GPSsatellite datatephraThree Sistervolcanic eruptionvolcano

ShareTweetShare
Mihai Andrei

Mihai Andrei

Dr. Andrei Mihai is a geophysicist and founder of ZME Science. He has a Ph.D. in geophysics and archaeology and has completed courses from prestigious universities (with programs ranging from climate and astronomy to chemistry and geology). He is passionate about making research more accessible to everyone and communicating news and features to a broad audience.

Related Posts

Astronomy

A NASA Spacecraft Just Spotted a Volcano on Mars Like We Have Never Seen Before

byTudor Tarita
1 week ago
Astronomy

Astronomers Found a Volcano Hiding in Plain Sight on Mars

byTudor Tarita
2 weeks ago
Geology

Scientists Found Traces of Gold Leaking from Earth’s Core

byTibi Puiu
1 month ago
Mind and Brain

Why Some People Never Get Lost — and Others Always Do

byTibi Puiu
1 month ago

Recent news

China Resurrected an Abandoned Soviet ‘Sea Monster’ That’s Part Airplane, Part Hovercraft

June 30, 2025
great white shark

This Shark Expert Has Spent Decades Studying Attacks and Says We’ve Been Afraid for the Wrong Reasons

June 30, 2025

A Rocket Carried Cannabis Seeds and 166 Human Remains into Space But Their Capsule Never Made It Back

June 30, 2025
  • About
  • Advertise
  • Editorial Policy
  • Privacy Policy and Terms of Use
  • How we review products
  • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.

No Result
View All Result
  • Science News
  • Environment
  • Health
  • Space
  • Future
  • Features
    • Natural Sciences
    • Physics
      • Matter and Energy
      • Quantum Mechanics
      • Thermodynamics
    • Chemistry
      • Periodic Table
      • Applied Chemistry
      • Materials
      • Physical Chemistry
    • Biology
      • Anatomy
      • Biochemistry
      • Ecology
      • Genetics
      • Microbiology
      • Plants and Fungi
    • Geology and Paleontology
      • Planet Earth
      • Earth Dynamics
      • Rocks and Minerals
      • Volcanoes
      • Dinosaurs
      • Fossils
    • Animals
      • Mammals
      • Birds
      • Fish
      • Amphibians
      • Reptiles
      • Invertebrates
      • Pets
      • Conservation
      • Animal facts
    • Climate and Weather
      • Climate change
      • Weather and atmosphere
    • Health
      • Drugs
      • Diseases and Conditions
      • Human Body
      • Mind and Brain
      • Food and Nutrition
      • Wellness
    • History and Humanities
      • Anthropology
      • Archaeology
      • History
      • Economics
      • People
      • Sociology
    • Space & Astronomy
      • The Solar System
      • Sun
      • The Moon
      • Planets
      • Asteroids, meteors & comets
      • Astronomy
      • Astrophysics
      • Cosmology
      • Exoplanets & Alien Life
      • Spaceflight and Exploration
    • Technology
      • Computer Science & IT
      • Engineering
      • Inventions
      • Sustainability
      • Renewable Energy
      • Green Living
    • Culture
    • Resources
  • Videos
  • Reviews
  • About Us
    • About
    • The Team
    • Advertise
    • Contribute
    • Editorial policy
    • Privacy Policy
    • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.