Cerro Azul

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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 0.92°S
  • 91.408°W

  • 1640 m
    5379 ft

  • 353060
  • Latitude
  • Longitude

  • Summit

  • Volcano

18 June-24 June 2008

According to news articles, a bulletin issued from Galápagos National Park indicated that eruptive activity from Cerro Azul decreased considerably during 16-17 June and on 18 June incandescent material was no longer ejected.

Source: EFE News Service

 Available Weekly Reports

2008: May | June

18 June-24 June 2008

According to news articles, a bulletin issued from Galápagos National Park indicated that eruptive activity from Cerro Azul decreased considerably during 16-17 June and on 18 June incandescent material was no longer ejected.

Source: EFE News Service

4 June-10 June 2008

Based on field observations, the IG reported on 5 June that the initial eruption on 29 May from the SE flank of Cerro Azul issued from three fissures. Six 'a'a lava flows up to 5 m thick flowed rapidly from a fissure near the caldera; one of the flows reached the next fissure at a lower elevation. A 1-km-long fissure in the central part of the flank emitted multiple lava flows up to 15 m thick. Activity at a third fissure at the lower flank, also about 1 km in length, produced cones and several lava flows.

On 3 June, new thermal anomalies on the SE flank detected in satellite imagery increased in intensity and migrated E in later images. Incandescence in the same area was also noted by ground observers. On 4 June an overflight confirmed the presence of a new vent. A fissure about 400-500 m long emitted lava flows that traveled towards the S coast of Isabela. Blocks were ejected about 60 m above the vents. A VAAC report indicated that an eruption plume drifted 50 km N. On 5 June, thermal anomalies were present on satellite imagery.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

28 May-3 June 2008

Based on information from the Galápagos National Park, observations of satellite imagery, and seismicity, the IG reported that Cerro Azul started to erupt on 29 May from several points along a radial fissure on the SE flank in the Cinco Cerros area. A thermal anomaly was present on satellite imagery at about the same time incandescence was seen through cloudiness in the direction of the volcano from ground observations. On 30 May, a plume, possibly with low ash content, was seen on satellite imagery drifting NW. An overflight and further observations revealed that lava flows traveled about 10 km down the SE flank over older flows from eruptions in 1978 and 1998. According to a news article, the lava flows were active during 29 May-1 June and burned vegetation on the flanks of the volcano.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Agence France-Presse (AFP)

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2008 May 29 2008 Jun 17 Confirmed 1 Historical Observations Summit and SE flank
1998 Sep 15 1998 Oct 21 Confirmed 1 Historical Observations N & W caldera floor, SE flank (630-680 m)
1979 Jan 29 1979 Mar 4 (in or after) Confirmed 2 Historical Observations East flank (300 m) and summit
[ 1968 Jun 12 ] [ Unknown ] Uncertain     North flank?
1959 Jun 29 1959 Jul 31 (?) Confirmed 2 Historical Observations East flank
1951 Unknown Confirmed   Historical Observations
1949 (?) Unknown Confirmed 0 Historical Observations
1948 Jun 30 ± 30 days Unknown Confirmed 0 Historical Observations
1943 Apr 13 ± 2 days 1943 May 11 (?) Confirmed 3 Historical Observations Caldera ring fracture
1940 Unknown Confirmed 0 Historical Observations East flank (Cerro de Las Animas)
1932 Unknown Confirmed 1 Historical Observations
1850 (after) Unknown Confirmed 1 Surface Exposure
1250 (after) Unknown Confirmed 0 Surface Exposure
0550 BCE ± 1000 years Unknown Confirmed 0 Surface Exposure
0950 BCE ± 1000 years Unknown Confirmed 0 Surface Exposure

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. 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. Additional discussion of data sources can be found under Volcano Data Criteria.

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

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

Mouginis-Mark P J, Snell H, Ellisor R, 2000. GOES satellite and field observations of the 1998 eruption of Volcan Cerro Azul, Galapagos Islands. Bull Volc, 62: 188-198.

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.

Naumann T, Geist D, Kurtz M, 2002. Petrology and geochemistry of Volcan Cerro Azul: petrologic diversity among the western Galapagos volcanoes. J Petr, 43: 859-883.

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.

Rowland S K, Harris A J L, Wooster M J, Amelung F, Garbeil H, Wilson L, Mouginis-Mark P J , 2003. Volumetric characteristics of lava flows from interferometric radar and multispectral satellite data: the 1995 Fernandina and 1998 Cerro Azul eruptions in the western Galapagos. Bull Volc, 65: 311-330.

Teasdale R, Geist D, Kurz M, Harpp K, 2005. 1998 eruption at Volcan Cerro Azul, Galapagos Islands: 1. Syn-eruptive petrogenesis. Bull Volc, 67: 170-185.

Located at the SW tip of the J-shaped Isabela Island, Cerro Azul contains a steep-walled 4 x 5 km nested summit caldera complex that is one of the smallest diameter, but at 650 m one of the deepest in the Galápagos Islands. The 1640-m-high shield volcano is the second highest of the archipelago. A conspicuous bench occupies the SW and west sides of the caldera, which formed during several episodes of collapse. Youthful lava flows cover much of the caldera floor, which has also contained ephemeral lakes. A prominent tuff cone located at the ENE side of the caldera is evidence of episodic hydrovolcanism at Cerro Azul. Numerous spatter cones dot the western flanks of the volcano. Fresh-looking lava flows, many erupted from circumferential fissures, descend the NE and NW flanks of the volcano. Historical eruptions date back only to 1932, but Cerro Azul has been one of the most active Galápagos volcanoes since that time. Solfataric activity continues within the caldera.