Isla Isabel

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 21.848°N
  • 105.886°W

  • 95 m
    312 ft

  • 341023
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for Isla Isabel.

The Global Volcanism Program has no Weekly Reports available for Isla Isabel.

The Global Volcanism Program has no Bulletin Reports available for Isla Isabel.

Isla Isabel, a complex of tuff cones and associated lava flows, forms a small 1.5-km-long island located in the Pacific Ocean 30 km off the coast of Narayit state, NW of the city of Tepic. Despite its apparent location at the western end of the Mexican Volcanic Belt, Isla Isabel consists of alkaline basaltic rocks and tephra similar to those of other Mexican island volcanoes and in the Northern Mexican Extensional Province. The island is a wildlife sanctuary whose rocks and vegetation are mantled with guano. Spectacular exposures of the interior of the tuff cones forming the island can be found in sea cliffs of the main island and offshore islets. The age of the most recent eruptive activity is not known, but morphology and a negative Argon-Argon age from a young sample suggests activity may have continued into the Holocene. One youthful-looking unvegetated lava flow of unknown age is located on the NW side of the island.

The Global Volcanism Program is not aware of any Holocene eruptions from Isla Isabel. If this volcano has had large eruptions (VEI >= 4) prior to 10,000 years ago, information might be found on the Isla Isabel page in the LaMEVE (Large Magnitude Explosive Volcanic Eruptions) database, a part of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

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.



Cones
Feature Name Feature Type Elevation Latitude Longitude
Acantilados Mayor Tuff cone
Acantilados Rabijuncos Tuff cone
Faro, Cerro el Tuff cone
Mirador, Cerro del Tuff cone 95 m
Pelicanos, Cerro de los Tuff cone
Transverso, Monte Tuff cone


Craters
Feature Name Feature Type Elevation Latitude Longitude
Fragatas, Lagunas Maar
Isla Isabel, a complex of tuff cones and associated lava flows, forms a small 1.5-km-long island located in the Pacific Ocean 30 km off the coast of Narayit state. The island is seen here from the SE with Cerro el Faro tuff cone at the left and the spires of the Islotes Las Monas at the right. Isla Isabel is a wildlife sanctuary whose rocks and vegetation are mantled with white-colored guano. Spectacular exposures of the interior of the tuff cones forming the island can be found in sea cliffs of the main island and offshore islets.

Photo by Jim Luhr, 1999 (Smithsonian Institution).
Wave erosion of a tuff cone off the western coast of Isla Isabel has produced the jagged profile of the 100-m-wide southernmost seastack in the Islotes Las Monas. The three guano-covered tuff cone remnants forming the Islotes Las Monas lie within about 200 m of the eastern coast of Isla Isabel, which can be seen at the right.

Photo by Jim Luhr, 1999 (Smithsonian Institution).
A sea-cliff exposure at the southern end of Islota Pelón, located off the NW coast of Isla Isabel, shows a dramatic angular uncomformity between two generations of dipping tuff beds. The large volcanic bomb perched on the rim at the top lies on dipping tuff beds in the interior of the tuff cone. Wave erosion has left only the arcuate western rim of Islota Pelón, whose vent lies out of view to the right.

Photo by Jim Luhr, 1999 (Smithsonian Institution).
Islota Pelón (upper left), just off the NW coast of Isla Isabel, is the outer rim of an elliptical, mostly submerged tuff cone whose SE rim (center) is located on the tip of the main island. The poorly distinguishable narrow dark gray streak extending diagonally from the lower right is part of the Planicie lava flow, which extends to the bay at the center of the photo and is the product of the youngest eruption on Isla Isabel.

Photo by Jim Luhr, 1995 (Smithsonian Institution).
Flat-topped Cerro El Faro tuff cone (upper right) lies across a low isthmus at the southernmost tip of Isla Isabel. It is seen here across the Acantilado Mayor Bay from Cerro del Mirador, the high point of the small 1.5-km-long island. Wave erosion has truncated the flank of Monte Transverso on the left. An olivine-basaltic lava flow forms the flat isthmus connecting the two tuff cones.

Photo by Jim Luhr, 1999 (Smithsonian Institution).
Buildings of a biological research station and fishermen's shacks line the shores of Playa Chica on the SE side of Isla Isabel. The two spires at the upper left are the Islotes Las Monas, eroded remnants of an offshore tuff cone. The lake-filled Laguna Fragatas maar can be seen at the left in front of the spires of the Islotes Las Monas. The small 1.5-km-wide uninhabited Isla Isabel is a wildlife sanctuary. Eruptive activity at Isla Isabel may have continued into the Holocene.

Photo by Jim Luhr, 1999 (Smithsonian Institution).

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.

Aranda-Gomez J J, 1999. . (pers. comm.).

Cabral-Cano E, Armienta-Hernandez M A, Urrutia-Fucugauchi J, 1990. Reconocimiento geologico y paleomagnetico en la Isla Isabel, Narayit, Mexico. Rev Geofis, 31: 161-184.

Housh T B, Aranda-Gomez J J, Luhr J F, 2010. Isla Isabel (Nayarit, Mexico): Quaternary alkalic basalts with mantle xenoliths erupted in the mouth of the Gulf of California. J Volc Geotherm Res, 197: 85-107.

Luhr J F, 1999. . (pers. comm.).

Volcano Types

Tuff cone(s)
Cinder cone(s)
Maar

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Rock Types

Major
Basalt / Picro-Basalt
Trachybasalt / Tephrite Basanite

Affiliated Databases

Large Eruptions of Isla Isabel 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.