Roundtop

Description Past Activity Images Maps Bibliography Prepare

Facts

Official Name: Roundtop Mountain
Seismically Monitored: No
Color Code: UNASSIGNED
Alert Level: UNASSIGNED
Elevation: 1871m (6138ft)
Latitude: 54.7992
Longitude: -163.5914
Smithsonian VNum: 311380
Pronunciation:
Nearby Towns:
- False Pass 8 mi (13 km) NE
- Pauloff Harbor 43 mi (69 km) SE
- Cold Bay 44 mi (70 km) NE
- King Cove 54 mi (87 km) NE
- Belkofski 65 mi (105 km) NE
Distance from Anchorage: 667 mi (1073 km)

Description

From Wood and Kienle (1990)^[1]: "Roundtop is an eroded and glaciated stratovolcano, located ~13 km southwest of the village of False Pass. In the 1930's warm springs were found on its slopes. Recent field study indicates the presence of Holocene pyroclastic flows and a group of domes south of Roundtop, as well as a thick silicic pre-Holocene flow."

Name Origin

This feature was reported as "Round Top" by the U.S. Coast and Geodetic Survey in 1902, and called "Dome" by J.F. Moser, U.S. Navy, in 1897 (Orth, 1971).

References Cited

[1] Volcanoes of North America: United States and Canada, 1990

Wood, C. A., and Kienle, Juergen, (eds.), 1990, Volcanoes of North America: United States and Canada: New York, Cambridge University Press, 354 p.

Reported Activity

Modern Eruptions

1 Event Date(s)

Past Activity Legend:

	Eruption
	Questionable eruption
	Non-eruptive activity

10000 yBP: Roundtop 10000 yBP

The northwest flank of Roundtop Mountain viewed from the high on the north flank of Isanotski Peaks.

Roundtop (left) and an unnamed peak (right) viewed from the north.

View of Roundtop Volcano on July 30, 2024, during AVO fieldwork on Unimak Island.

View of Isanotski Volcano on July 30, 2024, during AVO fieldwork on Unimak Island. Roundtop Volcano is seen at the background.

The southwest flank of Shishaldin Volcano viewed during a gas and structure-from-motion survey on July 30, 2024. Isanotski and Roundtop volcanoes are visible in the background.

Roundtop volcano from the south. Foreground is a creek drainage with large pyroclastic flow on the right side of the image.

Roundtop Mountain viewed from the south. Section of exposed pyroclastic density current (PDC) deposit visible at the bottom of the image.

Section of exposed pyroclastic density current deposit from Roundtop Mountain, south of the edifice. Helicopter and geologist visible at base of outcrop for scale.

Pyroclastic flow deposits at the southern flank of the Roundtop Volcano

Layers of ash from the late stages of the 2023 Shishaldin eruption observed at the summit of Roundtop Volcano. Ash samples 24IPE10A and 24IPE10B were collected from the upper and lower parts of the section, respectively. This image was captured during AVO fieldwork on Unimak Island in 2024.

False Pass, Alaska, with Roundtop Mountain visible at the head of the valley above the community.

View of Roundtop Volcano on July 28, 2024, during AVO fieldwork on Unimak Island.

Panorama image of Unimak Island volcanoes from south of Isanotski. From right to left: Roundtop Mountain, Isanotski Peaks, Shishaldin Volcano, Westdahl volcano.

Roundtop Mountain viewed from the south flank of Isanotksi.

AVO geologists collecting rock samples during 2024 fieldwork on Unimak Island

Shishaldin Volcano, west notch.<br />
Isanotski and Roundtop in background.

Photo of Shishaldin Volcano (center-right) on July 18, 2023, as an ash-rich plume erupted, taken from the air. View from the north of Shishaldin, with the ash-rich plume extending to the southeast. Isanotski volcano (center) and Roundtop (center-left) are also visible.

View of Isanotski, Roundtop, and Shishaldin from King Cove, July 14, 2023. Photo courtesy of Sean Mack.

From left to right: Shishaldin Volcano, Isanotski, Roundtop, Frosty, and Pavlof/Pavlof Sister volcanoes. Photo taken from the air, July 11, 2023.

Showing 1 - 20 of 74

Map Images

By: U.S. Geological Survey
Topographic map of Roundtop Volcano, on the northern part of Unimak Island, Alaska.

By: U.S. Geological Survey
Topographic map of Shishaldin, Isanotski, and Roundtop.

Map References

Volcanoes of Alaska, 1998

Nye, C. J., Queen, Katherine, and McCarthy, A. M., 1998, Volcanoes of Alaska: Alaska Division of Geological & Geophysical Surveys Information Circular IC 0038, unpaged, 1 sheet, scale 1:4,000,000, available at http://www.dggs.dnr.state.ak.us/pubs/pubs?reqtype=citation&ID=7043 .

website with links to sheets in PDF format

Hard Copy held by AVO at FBKS - CEC shelf

Revised geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula, 1997

Wilson, F. H., Weber, F. R., Dochat, T. M., Miller, T. P., and Detterman, R. L., 1997, Revised geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula: U.S. Geological Survey Open-File Report 97-0866, 34 p., 1 sheet, scale 1:250,000.

Geothermal resources of the Aleutian Arc, 1993

Motyka, R. J., Liss, S. A., Nye, C. J., and Moorman, M. A., 1993, Geothermal resources of the Aleutian Arc: Alaska Division of Geological & Geophysical Surveys Professional Report PR 0114, 17 p., 4 sheets, scale 1:1,000,000.

Hard Copy held by AVO at FBKS - CEC shelf

Holocene volcanoes of the Aleutian Arc, Alaska, 1993

March, G. D., 1993, Holocene volcanoes of the Aleutian Arc, Alaska: Alaska Division of Geological & Geophysical Surveys Public-Data File PDF 93-85, unpaged, 1 sheet, scale 1:2,000,000.

Preliminary geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula, 1992

Wilson, F. H., Miller, T. P., and Detterman, R. L., 1992, Preliminary geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula: U.S. Geological Survey Open-File Report 92-0545, 10 p., 1 plate, scale 1:250,000.

Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Alaska, 1986

Luedke, R. G., and Smith, R. L., 1986, Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I 1091-F, unpaged, 3 sheets, scale 1:1,000,000.

Reconnaissance geologic map of the Cold Bay and False Pass quadrangles, Alaska, 1978

McLean, H., Engelhardt, C. L., and Howell, D. G., 1978, Reconnaissance geologic map of the Cold Bay and False Pass quadrangles, Alaska: U.S. Geological Survey Open-File Report 78-0323, unpaged, 1 plate.

References

Proximity to active volcanoes enhances glacier velocity, 2024

Mallalieu, J., Barr, I.D., Spagnolo, M., Mullan, D.J., Symeonakis, E., Edwards, B.R., and Martin, M.D., 2024, Proximity to active volcanoes enhances glacier velocity: Communications Earth & Environment v. 5, 679. https://doi.org/10.1038/s43247-024-01826-5

Full-text PDF 1.3 MB

Supplementary data 80.5 MB

Geologic database of information on volcanoes in Alaska (GeoDIVA), 2022

Cameron, C.E., Crass, S.W., and AVO Staff, eds, 2022, Geologic database of information on volcanoes in Alaska (GeoDIVA): Alaska Division of Geologic and Geophysical Surveys Digital Data Series 20, https://doi.org/10.14509/geodiva, https://doi.org/10.14509/30901.

2018 update to the U.S. Geological Survey national volcanic threat assessment, 2018

Ewert, J.W., Diefenbach, A.K., and Ramsey, D.W., 2018, 2018 update to the U.S. Geological Survey national volcanic threat assessment: U.S. Geological Survey Scientific Investigations Report 2018-5140, 40 p., https://pubs.usgs.gov/sir/2018/5140/sir20185140.pdf.

download from USGS

Alaska Volcano Observatory image database, 2016

Cameron, C.E., and Snedigar, S.F., 2016, Alaska Volcano Observatory image database: Alaska Division of Geological & Geophysical Surveys Digital Data Series 13, https://www.avo.alaska.edu/images/. https://doi.org/10.14509/29689.

publication page at DGGS

AVO image database

Regional controls on volcano seismicity along the Aleutian Arc, 2014

Buurman, Helena, Nye, C.J., West, M.E., and Cameron, Cheryl, 2014, Regional controls on volcano seismicity along the Aleutian Arc: Geochemistry, Geophysics, Geosystems, doi:10.1002/2013GC005101

Preliminary database of Quaternary vents in Alaska, 2014

Cameron, C.E., and Nye, C.J., 2014, Preliminary database of Quaternary vents in Alaska: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 153, 11 p., doi:10.14509/27357 .

Preliminary spreadsheet of eruption source parameters for volcanoes of the world, 2009

Mastin, L.G., Guffanti, Marianne, Ewert, J.E., and Spiegel, Jessica, 2009, Preliminary spreadsheet of eruption source parameters for volcanoes of the world: U.S. Geological Survey Open-File Report 2009-1133, v. 1.2, 25 p., available at http://pubs.usgs.gov/of/2009/1133/ .

System for ranking relative threats of U.S. volcanoes, 2007

Ewert, John, 2007, System for ranking relative threats of U.S. volcanoes: Natural Hazards Review, v. 8, n. 4, p. 112-124.

An assessment of volcanic threat and monitoring capabilities in the United States: framework for a National Volcano Early Warning System NVEWS, 2005

Ewert, J.W., Guffanti, Marianne, and Murray, T.L., 2005, An assessment of volcanic threat and monitoring capabilities in the United States: framework for a National Volcano Early Warning System NVEWS: U.S. Geological Survey Open-File Report 2005-1164, 62 p.

full-text PDF 2.90 MB

Volcanoes of the world: an illustrated catalog of Holocene volcanoes and their eruptions, 2003

Siebert, L., and Simkin, T., 2002-, Volcanoes of the world: an illustrated catalog of Holocene volcanoes and their eruptions: Smithsonian Institution, Global Volcanism Program Digital Information Series GVP-3, http://volcano.si.edu/search_volcano.cfm, unpaged internet resource.

website

Bibliography of information on Alaska volcanoes, 2003

Cameron, C. E., Triplehorn, J. H., and Robar, C. L., 2003, Bibliography of information on Alaska volcanoes: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication MP 131, 1 CD-ROM.

Hard Copy held by AVO at FBKS - CEC file cabinet

Holocene tephrochronology of the Cold Bay area, southwest Alaska Peninsula, 2002

Carson, E. C., Fournelle, J. H., Miller, T. P., and Mickelson, D. M., 2002, Holocene tephrochronology of the Cold Bay area, southwest Alaska Peninsula: Quaternary Science Reviews, v. 21, n. 20-22, p. 2213-2228.

Hard Copy held by AVO at FBKS - CEC file cabinet

Newly identified early Holocene caldera-forming eruption from Roundtop Volcano, Unimak Island, Alaska, 1999

Miller, T. P., 1999, Newly identified early Holocene caldera-forming eruption from Roundtop Volcano, Unimak Island, Alaska [abs.]: Eos, v. 80, n. 46, p. 1190.

May-August 1999, 1999

Alaska Volcano Observatory, 1999, May-August 1999: Alaska Volcano Observatory Bimonthly Report, v. 11, n. 3 and 4, 39 p.

Part 1 PDF 399 KB

Part 2 PDF 831 KB

Part 3 PDF 736 KB

Part 4 PDF 41 KB

Part 5 PDF 91 KB

Volcanoes of Alaska, 1998

website with links to sheets in PDF format

Hard Copy held by AVO at FBKS - CEC shelf

Holocene tephrochronology of the Cold Bay area, Southwest Alaska Peninsula, 1998

Carson, E. C., 1998, Holocene tephrochronology of the Cold Bay area, Southwest Alaska Peninsula: University of Wisconsin-Madison unpublished M.S. thesis, 178 p.

Holocene tephrochronology of the Cold Bay area, Southwest Alaska Peninsula, 1998

Carson, E. C., and Fournelle, John, 1998, Holocene tephrochronology of the Cold Bay area, Southwest Alaska Peninsula: Abstracts with Programs - Geological Society of America, v. 30, n. 2, p. 9.

Hard Copy held by AVO at FBKS - CEC file cabinet

Revised geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula, 1997

Volcanoes of the Alaska Peninsula and Aleutian Islands selected photographs, 1997

Neal, Christina, and McGimsey, R. G., 1997, Volcanoes of the Alaska Peninsula and Aleutian Islands selected photographs: U.S. Geological Survey Digital Data Series DDS 0040, 1 CD-ROM.

website with links to HTML album, PDF, and individual images in a variety of formats

USGS website with links to photographs

July-August 1997, 1997

Alaska Volcano Observatory, 1997, July-August 1997: Alaska Volcano Observatory Bimonthly Report, v. 9, n. 4, 31 p.

Part 1 PDF 446 KB

Part 2 PDF 435 KB

Part 3 PDF 2 MB

Volcanoes of the world [2nd edition], 1994

Simkin, Tom, and Siebert, Lee, 1994, Volcanoes of the world [2nd edition]: Tucson, Arizona, Geoscience Press, 349 p.

Hard Copy held by AVO at FBKS - CEC shelf

Age, character, and significance of Aleutian arc volcanism, 1994

Fournelle, J. H., Marsh, B. D., and Myers, J. D., 1994, Age, character, and significance of Aleutian arc volcanism: in Plafker, George and Berg, H. C., (eds.), The Geology of Alaska, Geological Society of America The Geology of North America Series v. G-1, p. 723-758.

Quaternary volcanism in the Alaska Peninsula and Wrangell Mountains, Alaska, 1994

Miller, T. P., and Richter, D. H., 1994, Quaternary volcanism in the Alaska Peninsula and Wrangell Mountains, Alaska: in Plafker, George, Jones, D. L., and Berg, H. C., (eds.), The Geology of Alaska, Geological Society of America The Geology of North America series v. G-1, p. 759-779.

Hard Copy held by AVO at FBKS - CEC file cabinet

Geothermal resources of the Aleutian Arc, 1993

Hard Copy held by AVO at FBKS - CEC shelf

Holocene volcanoes of the Aleutian Arc, Alaska, 1993

March, G. D., 1993, Holocene volcanoes of the Aleutian Arc, Alaska: Alaska Division of Geological & Geophysical Surveys Public-Data File PDF 93-85, unpaged, 1 sheet, scale 1:2,000,000.

Oxygen isotope constraints on the petrogenesis of Aleutian arc magmas, 1992

Singer, B. S., O'Neil, J. R., and Brophy, J. G., 1992, Oxygen isotope constraints on the petrogenesis of Aleutian arc magmas: Geology, v. 20, n. 4, p. 367-370.

Preliminary geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula, 1992

Volcanoes of North America: United States and Canada, 1990

Wood, C. A., and Kienle, Juergen, (eds.), 1990, Volcanoes of North America: United States and Canada: New York, Cambridge University Press, 354 p.

Hard Copy held by AVO at FBKS - CEC shelf

Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Alaska, 1986

Volcanoes of the world, 1981

Simkin, Tom, Siebert, Lee, McClelland, Lindsay, Bridge, David, Newhall, Christopher, and Latter, J. H., 1981, Volcanoes of the world: Stroudsburg, PA, Hutchinson Publishing Company, 233 p.

Comprehensive tables giving physical data and thermal energy estimates for young igneous systems of the United States, 1978

Smith, R. L., Shaw, H. R., Luedke, R. G., and Russell, S. L., 1978, Comprehensive tables giving physical data and thermal energy estimates for young igneous systems of the United States: U.S. Geological Survey Open-File Report 78-0925, p. 1-25.

Hard Copy held by AVO at FBKS - CEC shelf

Reconnaissance geologic map of the Cold Bay and False Pass quadrangles, Alaska, 1978

Aleutian/Pribilof Islands region community profiles, 1978

Arctic Environmental Information and Data Center, 1978, Aleutian/Pribilof Islands region community profiles: unpaged.

Notes on the islands of the Unalashka district; and, Notes on the Atkhan Aleuts and the Kolosh [translated from Russian by Richard Henry Geogheghan], 1968

Veniaminov, Ivan, 1968, Notes on the islands of the Unalashka district; and, Notes on the Atkhan Aleuts and the Kolosh [translated from Russian by Richard Henry Geogheghan]: Martin, Fredericka, (ed.), Unpublished manuscript, Fairbanks, AK, 944 p.

Alaska Peninsula-Aleutian Islands, 1958

Powers, H. A., 1958, Alaska Peninsula-Aleutian Islands: in Williams, H., (ed.), Landscapes of Alaska, Los Angeles, CA, University of California Press, p. 61-75.

Glaciers of the Aleutian Islands, 1945

Denton, G. H., 1945, Glaciers of the Aleutian Islands: in Field, W. O., (ed.), Mountain glaciers of the Northern Hemisphere, v. 2, Hanover, NH, Cold Regions Research and Engineering Laboratory, p. 641-650.

The Aleutian and Commander Islands and their inhabitants, 1945

Hrdlicka, Ales, 1945, The Aleutian and Commander Islands and their inhabitants: Philadelphia, PA, Wistar Institute of Anatomy and Biology, 630 p.

Hard Copy held by AVO at FBKS - CEC file cabinet

Cradle of the storms, 1935

Hubbard, B. R., 1935, Cradle of the storms: New York, Dodd, Mead, 285 p.

Shishaldin volcano, 1934

Finch, R. H., 1934, Shishaldin volcano: in Pacific Science Congress, 5, Proceedings, v. 3, Victoria and Vancouver, BC, 1933, p. 2369-2376.

Hard Copy held by AVO at FBKS - CEC file cabinet

Mountains on Unimak Island, Alaska, 1903

Westdahl, F., 1903, Mountains on Unimak Island, Alaska: National Geographic Magazine, v. 14, n. 3, p. 91-99.

Hard Copy held by AVO at FBKS - CEC file cabinet

Notes on the islands of the Unalaska district [translated from Russian by Lydia T. Black and R.H. Geoghegan in 1984], 1840

Veniaminov, Ivan, 1840, Notes on the islands of the Unalaska district [translated from Russian by Lydia T. Black and R.H. Geoghegan in 1984]: Pierce, R. A., (ed.), Kingston, Ontario, Limestone Press, 511 p.

Hard Copy held by AVO at FBKS - CEC file cabinet

Notes on the islands of the Unalashka district [Zapiski ob ostravakh Unalashkinskogo otdela], 1840

Veniaminov, I., 1840, Notes on the islands of the Unalashka district [Zapiski ob ostravakh Unalashkinskogo otdela]: v. 1-3, St. Petersburg, Russiisko-Amerikanskoi Kompanii, unknown.

Past volcanic activity in the Aleutian arc,

Coats, R. R., Past volcanic activity in the Aleutian arc: U.S. Geological Survey Volcano Investigations Report 1, 18 p.

full-text PDF 22.3 MB

	Red (Warning)
	Orange (Watch)
	Yellow (Advisory)
	Green (Normal)
	Uninstrumented
	Community
	Webcam
	Instrument
	Earthquake

Alaska Volcano Observatory

Roundtop

Facts

Description

Name Origin

References Cited

[1] Volcanoes of North America: United States and Canada, 1990

Reported Activity

Modern Eruptions

1 Event Date(s)

Map Images

Map References

Volcanoes of Alaska, 1998

Revised geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula, 1997

Geothermal resources of the Aleutian Arc, 1993

Holocene volcanoes of the Aleutian Arc, Alaska, 1993

Preliminary geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula, 1992

Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Alaska, 1986

Reconnaissance geologic map of the Cold Bay and False Pass quadrangles, Alaska, 1978

References

Proximity to active volcanoes enhances glacier velocity, 2024

Geologic database of information on volcanoes in Alaska (GeoDIVA), 2022

2018 update to the U.S. Geological Survey national volcanic threat assessment, 2018

Alaska Volcano Observatory image database, 2016

Regional controls on volcano seismicity along the Aleutian Arc, 2014

Preliminary database of Quaternary vents in Alaska, 2014

Preliminary spreadsheet of eruption source parameters for volcanoes of the world, 2009

System for ranking relative threats of U.S. volcanoes, 2007

An assessment of volcanic threat and monitoring capabilities in the United States: framework for a National Volcano Early Warning System NVEWS, 2005

Volcanoes of the world: an illustrated catalog of Holocene volcanoes and their eruptions, 2003

Bibliography of information on Alaska volcanoes, 2003

Holocene tephrochronology of the Cold Bay area, southwest Alaska Peninsula, 2002

Newly identified early Holocene caldera-forming eruption from Roundtop Volcano, Unimak Island, Alaska, 1999

May-August 1999, 1999

Volcanoes of Alaska, 1998

Holocene tephrochronology of the Cold Bay area, Southwest Alaska Peninsula, 1998

Holocene tephrochronology of the Cold Bay area, Southwest Alaska Peninsula, 1998

Revised geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula, 1997

Volcanoes of the Alaska Peninsula and Aleutian Islands selected photographs, 1997

July-August 1997, 1997

Volcanoes of the world [2nd edition], 1994

Age, character, and significance of Aleutian arc volcanism, 1994

Quaternary volcanism in the Alaska Peninsula and Wrangell Mountains, Alaska, 1994

Geothermal resources of the Aleutian Arc, 1993

Holocene volcanoes of the Aleutian Arc, Alaska, 1993

Oxygen isotope constraints on the petrogenesis of Aleutian arc magmas, 1992

Preliminary geologic map of the Cold Bay and False Pass quadrangles, Alaska Peninsula, 1992

Volcanoes of North America: United States and Canada, 1990

Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Alaska, 1986

Volcanoes of the world, 1981

Comprehensive tables giving physical data and thermal energy estimates for young igneous systems of the United States, 1978

Reconnaissance geologic map of the Cold Bay and False Pass quadrangles, Alaska, 1978

Aleutian/Pribilof Islands region community profiles, 1978

Notes on the islands of the Unalashka district; and, Notes on the Atkhan Aleuts and the Kolosh [translated from Russian by Richard Henry Geogheghan], 1968

Alaska Peninsula-Aleutian Islands, 1958

Glaciers of the Aleutian Islands, 1945

The Aleutian and Commander Islands and their inhabitants, 1945

Cradle of the storms, 1935

Shishaldin volcano, 1934

Mountains on Unimak Island, Alaska, 1903

Notes on the islands of the Unalaska district [translated from Russian by Lydia T. Black and R.H. Geoghegan in 1984], 1840

Notes on the islands of the Unalashka district [Zapiski ob ostravakh Unalashkinskogo otdela], 1840

Past volcanic activity in the Aleutian arc,

Before an eruption

Ashfall & Preparedness Information

Useful Links