Data from the Global Volcanism Program of the Smithsonian Institution
Details for: Negra, Sierra
An aerial view of the SW caldera floor of Sierra Negra volcano shows El Azufre fumarolic field and the trap-door fault to the left. This sinuous 14-km-long, N-S-trending ridge occupies the west part of the caldera floor, which lies only about 100 m below its rim. El Azufre, the largest fumarolic area in the Galápagos Islands, lies within a graben between this ridge and the west caldera wall. The broad shield volcano of Sierra Negra at the southern end of Isabela Island contains a shallow 7 x 10.5 km caldera that is the largest in the Galápagos Islands. Photo by Patricio Ramon, 2005 (Instituto Geofisca, Escuela Politecnica Nacional).
Volcano Number:353050
Volcano Name:Negra, Sierra
Country:Ecuador
Volcano Type:Shield
Last Eruption:2018
Elevation:1124m
Tectonic Setting:Rift zone / Oceanic crust (< 15 km)
Pop. within 5km:408
Pop. within 10km:408
Pop. within 30km:983
Pop. within 100km:9884
Latitude:-0.83
Longitude:-91.17



Eruption Data from the Global Volcanism Program of the Smithsonian Institution
Volcano Number Volcano Name Eruption Number Activity Type Explosivity Index Max Explosivity Index Modifier Activity Area Activity Unit Start Evidence Method Start Date End Date
353050 Negra, Sierra 11697 Confirmed Eruption 0 Surface Exposure -8250
353050 Negra, Sierra 11698 Confirmed Eruption 0 SE flank Radiocarbon (uncorrected) -1250
353050 Negra, Sierra 11699 Confirmed Eruption 0 Surface Exposure 370
353050 Negra, Sierra 11700 Confirmed Eruption 0 Surface Exposure 1060
353050 Negra, Sierra 11701 Confirmed Eruption 0 Surface Exposure 1350
353050 Negra, Sierra 11702 Confirmed Eruption 2 ? Volcano Uncertain: South end of Isabela Island 1813/7/13
353050 Negra, Sierra 11703 Confirmed Eruption Volcano Uncertain: Isabela Island 1817
353050 Negra, Sierra 11704 Confirmed Eruption 0 Volcano Uncertain: Isabela Island 1844
353050 Negra, Sierra 11705 Confirmed Eruption 2 Volcano Uncertain: Isabela Island 1860
353050 Negra, Sierra 11706 Confirmed Eruption Historical Observations 1911/12/31
353050 Negra, Sierra 11707 Confirmed Eruption 2 Historical Observations 1948 1949
353050 Negra, Sierra 11708 Confirmed Eruption 3 ? Volcán Chico area & NW caldera rim Historical Observations 1953/8/27 1954/1/16
353050 Negra, Sierra 11709 Confirmed Eruption 2 Volcano Uncertain: originally Alcedo 1954/11/9
353050 Negra, Sierra 11710 Confirmed Eruption Volcano Uncertain: Isabela Island 1957/7/2
353050 Negra, Sierra 11711 Confirmed Eruption 2 Volcán Chico area & NW caldera rim Historical Observations 1963/4/13 1963/5/16
353050 Negra, Sierra 11712 Confirmed Eruption 3 Upper NW and NE flanks (Volcán Chico) Historical Observations 1979/11/13 1980/1/14
353050 Negra, Sierra 11713 Confirmed Eruption 3 North caldera rim Historical Observations 2005/10/22 2005/10/30
353050 Negra, Sierra 22279 Confirmed Eruption 2 Summit crater and NNW flank Historical Observations 2018/6/26 2018/8/23
Emissions Data from the Global Volcanism Program of the Smithsonian Institution
Emission ID SO2 Kilotons Start Date End Date
314 2524 1979/11/13 1979/11/13
315 1928 2005/10/23 2005/10/23


Data from the Earthchem Portal


Data from the SESAR Database


Data from the MaGa Database
Location: Sierra Negra caldera (View Details at MaGa DB)
Description: Sierra Negra is the largest shield volcano of Isabela Island in the Galapagos, hosting a 9×10 km elliptical caldera. Eruptive centers and different lava fields are subdivided into five distinctive age groups, all being less than 5,000 years old. Fumarolic activity inside Sierra Negra is fault controlled and occurs in an area known as Mina Azufral.
Hazard Description: not reported
Type: soil_diffuse_emission
Region: Galápagos Islands, Ecuador
Country: Ecuador
Volcanic Complex: Sierra Negra
Gas Flux Data:
Measurement Name Detail Specie Flux Std. Dev. Unit of Measure
Sierra Negra_01062006 Detail CO2 990 85 Mg/d

Location: Sierra Negra caldera fumarole (View Details at MaGa DB)
Description: Sierra Negra is the largest shield volcano of Isabela Island in the Galapagos, hosting a 9×10 km elliptical caldera. Eruptive centers and different lava fields are subdivided into five distinctive age groups, all being less than 5,000 years old. Fumarolic activity inside Sierra Negra is fault controlled and occurs in an area known as Mina Azufral.
Hazard Description: not reported
Type: fumarole
Region: Galápagos Islands, Ecuador
Country: Ecuador
Volcanic Complex: Sierra Negra
Gas Concentration Data:
Measurement Name Detail Specie Concentration Unit of Measure
Mina Azufral_01062006 Detail H2O 73.6
Mina Azufral_01062006 Detail CO2 97.4
Mina Azufral_01062006 Detail H2S 0.6
Mina Azufral_01062006 Detail SO2 1.5
Mina Azufral_01062006 Detail N2 0.349
Mina Azufral_01062006 Detail H2 0.0124
Mina Azufral_01062006 Detail He 0.00068
Mina Azufral_01062006 Detail CO 1.8E-5
Gas Flux Data:
Measurement Name Detail Specie Flux Std. Dev. Unit of Measure
Mina Azufral_01062006 Detail H2O 562 0 Mg/d
Mina Azufral_01062006 Detail CO2 394 0 Mg/d
Mina Azufral_01062006 Detail SO2 11 2 Mg/d
Mina Azufral_01062006 Detail H2S 3 0 Mg/d
Gas Temperature Data:
Measurement Name Detail Temperature Unit of Measure
Mina Azufral_01062006 Detail 207 °C