Wolf

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 0.02°N
  • 91.35°W

  • 1710 m
    5609 ft

  • 353020
  • Latitude
  • Longitude

  • Summit
    Elevation

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Most Recent Bulletin Report: August 1982 (SEAN 07:08)


Lava fountaining and flows in caldera and on SE flank

Eruption clouds began to emerge from the volcano during the afternoon of 28 August. Plume emission was first detected on visible band satellite images between 1300 and 1400, and feeding continued until nightfall. The plume, which drifted W, could not be seen on infrared imagery, indicating that it remained at low altitudes. Observers on a tour ship first saw clouds issuing from the summit about 1430-1500 and reported strong summit glow that night. Activity on the SE flank was first observed at 0830 the next morning, but heavy weather clouds had obscured this area the previous afternoon, and flank vents may have been active then as well.

Tui DeRoy Moore and others arrived at the SE flank late 31 August. Lava fountained from a radial fissure that extended 1 km or more downslope from 875 m altitude. Fresh lava covered the area near the fissure. Lava flowed SE then turned toward the E, reaching about 280 m altitude. This flow had stopped advancing by 1 September and fountaining had ended by that evening, although some SE flank glow remained visible. As the flank activity declined, summit activity increased. Summit glow had been visible since 28 August, but strengthened during the night of 1-2 September and a large convecting cloud was present over the caldera. Moore reached the caldera rim on 3 September and found several vents active in the caldera, the strongest on its floor at the base of the steep SW wall. Lava fountaining from this vent was continuous and the fountains occasionally rose as high as the caldera rim, approximately 700 m above the floor. Intermittent, relatively weak fountaining (less than 50 m estimated height) occurred from four small vents along a 100-200-m-long fissure on the S caldera floor. Thick-looking pahoehoe lava covered slightly more than half of the caldera floor, or approximately 6 km2, and was mainly on the N and NW side. Gases emerging from the base of the convecting eruption cloud formed a haze that drifted W, away from the observers. By early 4 September, when Moore left the volcano, a cone had begun to form around the main vent. Activity appeared to be dominated by scoria ejection, with little lava being added to the caldera floor flows. No earthquakes were felt by the observers, and Moore reported that there seemed to be little effect on the flora and fauna. Glow was still visible in the eruption cloud late 5 September and airplane passengers saw a strong plume 6 September.

Wolf has been one of the more active Galápagos volcanoes. Flank eruptions from the same SE vent area took place in 1948 and 1963, but summit caldera activity had not been documented since 1800. A probable SE flank eruption was heard but not seen in 1973. The present eruption is a two-hemisphere event, with the caldera lying mostly N of the equator and the SE vent, less than 10 km distant, in the Southern Hemisphere.

Further Reference. Schatz, H., and Schatz, I., 1983, Der ausbruch des Vulkanes Wolf (Inseln Isabela, Galápagos-Inseln Ecuador) im Jahre 1982—Ein Augenzeugenbericht; Ber. Nat. Med. Verein Innsbruck; v. 70, p. 17-28.

Information Contacts: T. Moore, Isla Santa Cruz, Galápagos.

The Global Volcanism Program has no Weekly Reports available for Wolf.

Index of Bulletin Reports


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

07/1971 (CSLP 42-71) Aerial reconnaissance shows caldera unchanged

03/1973 (CSLP 31-73) Earthquake swarm near Isla Isabella

11/1973 (CSLP 147-73) Park wardens hear strong and constant rumbling from the caldera

12/1973 (CSLP 150-73) Thermal anomalies, but no confirmed activity

08/1982 (SEAN 07:08) Lava fountaining and flows in caldera and on SE flank




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


07/1971 (CSLP 42-71) Aerial reconnaissance shows caldera unchanged

Card 1249 (07 July 1971) Aerial reconnaissance shows caldera unchanged

Information Contacts: Educational Expeditions International Research Team, Galapagos Islands, Ecuador; T. Simkin, SI.

03/1973 (CSLP 31-73) Earthquake swarm near Isla Isabella

Card 1588 (21 March 1973) Earthquake swarm near Isla Isabella

A small earthquake swarm took place in the Galapagos Islands in late January 1973. The Charles Darwin Research Station reported 57 events on its seismograph (GIE) from 23 through 28 January and estimated an epicentral distance of 110-160 km. The NOS/NOAA National Earthquake Information Center has located hypocenters for three events (Mb 4.4 and 4.5). These fit the Research Station's estimates, and are 15 km E, 26 km E, and 5 km SW of the center of Wolf, Isla Isabella. Dr. John Filson reports additional events (Mb 4.0-4.3) detected by LASA on 16 January and 18 February; the latter events are confirmed by NOS/NOAA but reliable hypocenters have not yet been located. The Charles Darwin Research Station reports no visible activity associated with this earthquake swarm.

Information Contacts: R. Sievers, Charles Darwin Research Station, Galapagos Islands, Ecuador; W. Person, U.S. National Earthquake Information Center; J. Filson, Massachusetts Institute of Technology; T. Simkin, SI.

11/1973 (CSLP 147-73) Park wardens hear strong and constant rumbling from the caldera

Card 1749 (30 November 1973) Park wardens hear strong and constant rumbling from the caldera

"Galapagos National Park Wardens on W flank of Wolf two weeks ago heard strong and constant rumbling from caldera. The roar could be heard at the coast 6 km from the caldera rim and continued through the night. No reports of eruptive cloud, but clouds frequently obscure summit and volcano cannot be seen from inhabited parts of the archipelago. Darwin Station seismograph reports no unusual activity, but earthquake swarm early this year (see Event Card 1588) appeared centered on the SE flank of Wolf, the site of the last, largest (Mb 4.9), and best-located event on 19 March 1973. Darwin Station party is en route to investigate and SKYLAB will photograph.

"The last recorded eruptions of this, the northernmost shield volcano on the largest Galapagos Island, were on the SE flank in 1948 and 1963. The equator crosses the S end of the caldera at 91.3°W and the rim is 6 km in diameter, 1,710 m above the sea, and 670 m above the caldera floor. Reports of Galapagos volcanism in early August of this year appear to have been influenced by NASA press release on successful SKYLAB photography of 'Galapagos Eruptive Centers.' No Galapagos eruption was sighted by SKYLAB II but shortly after the press release emerged from Ecuadorian newspapers clouds and lights were reported from the volcano at Cape Berkeley, NW Isabella. These reports have been investigated on the volcano by Darwin Station personnel and no evidence of an August eruption has been found. The only other Galapagos volcanism known since the 1968 Fernandina caldera collapse is the 1972 Fernandina eruption reported in June of this year (Event Card 1659). . . ."

Information Contacts: Peter Kramer, Charles Darwin Research Station, Galapagos Islands, Ecuador; Tom Simkin, SI.

12/1973 (CSLP 150-73) Thermal anomalies, but no confirmed activity

Card 1752 (13 December 1973) Space-based observations of activity

Observations from space... support previous indication of eruption on Wolf (Event Card 1749), and suggest strong thermal activity on Darwin. . . . NOAA-2 [satellite imagery] shows additional hot spots on E flank of Wolf . . . .

Card 1757 (17 December 1973) Infrared hot-spot probably not eruption related

Close inspection of NOAA-2 imagery shows hot spots reported on Event Card 1752 coincide with caldera floors, not outer flanks, and can probably be explained by normal daytime temperature differences. . . . Darwin Station party "saw nothing on Wolf" but gave no further details on that eruption (Event Card 1749).

Information Contacts: Card 1752 (13 December 1973) F. Parmenter, NOAA; M. McEwen, NASA; J. Filson, MIT; T. Simkin, SI.
Card 1757 (17 December 1973) A. Krueger and F. Parmenter, NOAA; J. Filson, MIT; P. Kramer, Darwin Research Station; T. Simkin, SI.

08/1982 (SEAN 07:08) Lava fountaining and flows in caldera and on SE flank

Eruption clouds began to emerge from the volcano during the afternoon of 28 August. Plume emission was first detected on visible band satellite images between 1300 and 1400, and feeding continued until nightfall. The plume, which drifted W, could not be seen on infrared imagery, indicating that it remained at low altitudes. Observers on a tour ship first saw clouds issuing from the summit about 1430-1500 and reported strong summit glow that night. Activity on the SE flank was first observed at 0830 the next morning, but heavy weather clouds had obscured this area the previous afternoon, and flank vents may have been active then as well.

Tui DeRoy Moore and others arrived at the SE flank late 31 August. Lava fountained from a radial fissure that extended 1 km or more downslope from 875 m altitude. Fresh lava covered the area near the fissure. Lava flowed SE then turned toward the E, reaching about 280 m altitude. This flow had stopped advancing by 1 September and fountaining had ended by that evening, although some SE flank glow remained visible. As the flank activity declined, summit activity increased. Summit glow had been visible since 28 August, but strengthened during the night of 1-2 September and a large convecting cloud was present over the caldera. Moore reached the caldera rim on 3 September and found several vents active in the caldera, the strongest on its floor at the base of the steep SW wall. Lava fountaining from this vent was continuous and the fountains occasionally rose as high as the caldera rim, approximately 700 m above the floor. Intermittent, relatively weak fountaining (less than 50 m estimated height) occurred from four small vents along a 100-200-m-long fissure on the S caldera floor. Thick-looking pahoehoe lava covered slightly more than half of the caldera floor, or approximately 6 km2, and was mainly on the N and NW side. Gases emerging from the base of the convecting eruption cloud formed a haze that drifted W, away from the observers. By early 4 September, when Moore left the volcano, a cone had begun to form around the main vent. Activity appeared to be dominated by scoria ejection, with little lava being added to the caldera floor flows. No earthquakes were felt by the observers, and Moore reported that there seemed to be little effect on the flora and fauna. Glow was still visible in the eruption cloud late 5 September and airplane passengers saw a strong plume 6 September.

Wolf has been one of the more active Galápagos volcanoes. Flank eruptions from the same SE vent area took place in 1948 and 1963, but summit caldera activity had not been documented since 1800. A probable SE flank eruption was heard but not seen in 1973. The present eruption is a two-hemisphere event, with the caldera lying mostly N of the equator and the SE vent, less than 10 km distant, in the Southern Hemisphere.

Further Reference. Schatz, H., and Schatz, I., 1983, Der ausbruch des Vulkanes Wolf (Inseln Isabela, Galápagos-Inseln Ecuador) im Jahre 1982—Ein Augenzeugenbericht; Ber. Nat. Med. Verein Innsbruck; v. 70, p. 17-28.

Information Contacts: T. Moore, Isla Santa Cruz, Galápagos.
Download or Cite this Report

Wolf, the highest volcano of the Galápagos Islands, straddles the equator at the north end of the archipelago's largest island, Isabela. The 1710-m-high edifice has steeper slopes than most other Isabela volcanoes, reaching angles up to 35 degrees. A 6 x 7 km caldera, at 700 m one of the deepest of the Galápagos Islands, is located at the summit. A prominent bench on the west side of the caldera rises 450 above the caldera floor, much of which is covered by a lava flow erupted in 1982. Radial fissures concentrated along diffuse rift zones extend down the north, NW, and SE flanks, and submarine vents lie beyond the north and NW fissures. Similar unvegetated flows originating from a circumferential chain of spatter and scoria cones on the eastern caldera rim drape the forested flanks to the sea. The proportion of aa lava flows at Volcán Wolf exceeds that of other Galápagos volcanoes. An eruption in in 1797 was the first documented historical eruption in the Galápagos Islands.

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1982 Aug 28 1982 Sep 6 (?) Confirmed 1 Historical Observations Caldera and SE flank (875 m)
[ 1973 Oct 25 ] [ 1973 Oct 29 ] Uncertain    
1963 Mar 4 1963 Mar 16 (in or after) Confirmed 0 Historical Observations SE flank (610 m)
1948 Jan 24 1948 Jan 31 (in or after) Confirmed 2 Historical Observations SE flank (1200 m)
1938 Unknown Confirmed   Historical Observations
1935 Feb Unknown Confirmed   Historical Observations
1933 Unknown Confirmed 0 Historical Observations
1925 Apr 11 1926 Mar 26 (in or after) Confirmed 1 Historical Observations ESE flank
1859 Aug 26 1859 Aug 29 Confirmed   Historical Observations
1849 Sep 27 1849 Sep 27 Confirmed   Historical Observations Volcano Uncertain: either Wolf or Darwin
1800 Aug 21 1800 Aug 21 Confirmed 2 Historical Observations
1797 Aug Unknown Confirmed   Historical Observations
1450 (after) Unknown Confirmed 0 Surface Exposure Lower NE and SE flanks
0950 (after) Unknown Confirmed 0 Surface Exposure Lower NE flank
0150 ± 800 years Unknown Confirmed 0 Surface Exposure Lower SW flank

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.


Synonyms

Whiton, Mount
Wolf, the highest volcano of the Galápagos Islands, straddles the equator at the north end of the archipelago's largest island, Isabela. Volcán Wolf shield volcano has steeper slopes than most other Isabela volcanoes. A 5.5 x 7 km caldera, 600 m deep, is located at the volcano's summit. The broad caldera floor is largely covered by fresh, unvegetated lava flows. Prominent unvegetated lava flows drape forested eastern flanks of the volcano to the sea. Wolf's 1797 eruption was the first documented in the Galápagos Islands.

Photo by Lee Siebert, 1978 (Smithsonian Institution).
A radial fissure on the NE flank of Volcán Wolf has produced extensive lava flows that in part lap onto the flanks of the main shield volcano. A sharp break in slope separates the low-angle flank rift zone, whose smooth profile is interrupted by a few small cinder cones, from the upper shield volcano, which has some of the steepest slopes of Galápagos shield volcanoes. A fresh unvegetated lava flow from the main shield at the extreme left was deflected to the south by the lava produced from the NE rift.

Photo by Lee Siebert, 1978 (Smithsonian Institution).
This dramatic Space Shuttle photo from a 1988 mission shows five major calderas of the Galápagos Islands. Caldera diameters capping these basasltic shield volcanoes range up to 8 km. At the lower left is Fernandina volcano. At the lower right is mostly vegetated Alcedo volcano on Isabela Island. Above and to the left is Darwin volcano, with the two prominent breached tuff cones, Tagus and Beagle, on its SW flank. Volcán Wolf is at the top of the photo, and Volcán Ecuador with its breached caldera forms the NW tip of Isabela Island.

Shuttle photo by National Aeronautical and Space Administration (NASA), 1988.
Volcán Ecuador (left center) forms the tip of a peninsula straddling the equator at the NW end of Isabela Island. The western side of the volcano, the smallest of the six large shield volcanoes on Isabela, is breached nearly to sea level. A line of fissure-fed vents on the outer eastern flank can be seen connecting Volcán Ecuador with Volcán Wolf (upper right). Despite the absence of historical eruptions from Volcán Ecuador, the youthful morphology of its most recent lava flows resembles those of very recent flows on other Isabela Island volcanoes.

Photo by National Aeronautical and Space Administration (NASA), 1988.
An aerial view from the north looks across the 6 x 7 km wide summit caldera of Volcán Wolf. Fresh-looking, dark-colored lava flows, erupted from fissures on the eastern and western caldera walls, cover much of the caldera floor. At 1710 m, Wolf is the highest of the Isabella Island shield volcanoes.

Photo by Patricio Ramon, 2005 (Instituto Geofisca, Escuela Politecnica Nacional).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

Delano, A, 1817. Narrative of Voyages and Travels in the Northern and Southern Hemispheres: Comprising Three Voyages Round the World; Together with a Voyage of Survey and Discovery, in the Pacific Ocean and Oriental Islands.. E.G. House, Boston.

Geist D J, Naumann T R, Standish J J, Kurz M D, Harpp K S, White W M, Fornari D J, 2005. Wolf volcano, Galapagos archipelago: melting and magmatic evolution at the margins of a mantle plume. J Petr, 46: 2197-2224.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

MARY WILDER (Ship) New Bedford, 1859. Journal, April 1, 1859-Nov. 5, 1859. Abner F. Barker, Master. Nicholson Whaling Collection, Providence Public Library, Providence, RI. Reel 448. Transcribed by K. Thalia Grant (2014)..

McBirney A R, Williams H, 1969. Geology and petrology of the Galapagos Islands. Geol Soc Amer Mem, 118: 1-197.

Naumann T, Geist D, 2000. Physical volcanology and structural development of Cerro Azul volcano, Isabela Island, Galapagos: implications for the development of Galapagos-type shield volcanoes.. Bull Volc, 61: 497-514.

Richards A F, 1962. Archipelago de Colon, Isla San Felix and Islas Juan Fernandez. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 14: 1-50.

Veeder, Susan C. Austin, 1853. Journal of the Whaleship Nauticon, September 13, 1848 - March 24, 1853. Charles Veeder, Master.. Nantucket Historical Association, NHA Manuscript Collection 220, Log 347. Digital Exhibition. Transcribed by K. Thalia Grant (2014)..

Wilson, G H, 1861. Journal, Jan. 30, 1859-May 3, 1861. On the bark OSCEOLA 3D, New Bedford. Otis F. Hamblin, Master. Nicholson Whaling Collection, Providence Public Library, Providence, RI. Reel 532. Transcribed by K. Thalia Grant (2014)..

Volcano Types

Shield
Caldera
Pyroclastic cone(s)

Tectonic Setting

Rift zone
Oceanic crust (< 15 km)

Rock Types

Major
Basalt / Picro-Basalt

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
165
165
237
1,673

Affiliated Databases

Large Eruptions of Wolf Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.