Izalco Volcano | John Seach


El Salvador

13.81 N, 89.63 W
summit elevation 1965 m

Izalco Volcano is located 45 km NW of San Salvador, El Salvador.  It is a parasitic cone located 4 km south and seaward from Santa Ana volcano. The summit contains a 200 m wide, 40 m deep crater. The volcano was in regular eruption between 1770 and 1966.

Currently Izalco Volcano is in its longest repose since its birth.

Izalco is El Salvador's youngest volcano. Izalco volcano has formed a 650 m high cone since its birth in 1770. Before the birth of the volcano in 1770 the mountain was 1300 m above sea level. Eruptions at the volcano have produced alternate lava flows and tephra ejection.

High-temperature minerals have been discovered in the summit crater fumaroles of Izalco volcano, including shcherbinaite, bannermanite, stoiberite, fingerite, ziesite, blossite and mcbirneyite.

In 1963 a new Vanadium compound was discovered in summit crater fumaroles at Izalco volcano. Additional Vanadium compounds have been discovered at the volcano since then, with some being designated new minerals.

The craters of Izalco and Santa Ana are separated by only 4 km, but there is marked contrast in the chemical composition of the lavas produced. Izalco flows have markedly higher Al2O3, CaO and Sr, and lower incompatible elements (Zr, Rb, K, Ba and TiO2).

1999 Fumarolic Activity
An increase in fumarolic activity was observed at the summit of Izalco volcano. Activity also increased in November 1998 following Hurricane Mitch.

1973 Thermal activity
An infrared reading registered temperatures 8 degrees above ambient at a location 50 m below the summit on 7th July 1973.

1966 Eruption
An eruption of Izalco volcano began on 28th October 1966 from a vent 550 meters below the summit on SSE flank. This area was also active in 1946. Two 10 m thick lava flows extended south for 1.2 km. The volume of lava erupted amounted to half of the shallow magma storage. Four of the larger hot fumaroles contribute at least 10% of the heat loss from the shallow magma storage, and heat conduction accounted for half the heat loss.

1954-57 Eruptions
Three lava flows erupted in the crater between 1954 and 1957.

1924 Eruptions
On 24th October 1924 there were explosions and emissions of small fragments of incandescent lava at Izalco volcano. Activity ended on 10th November and resumed on 21st December.

1920-21 Eruptions
Eruptive activity began on 29th October 1920 on the SE flank, and ended on 1st April 1921. The volcano remained inactive except for fumarolic activity until 4th March 1924 when armeniano crater became active.

Izalco Volcano Eruptions

1966, 1948-57, 1939-48, 1937?-38?, 1933-34, 1931, 1930, 1927-28?, 1925-27, 1924, 1920-21, 1912-16, 1903-05, 1902, 1899-1900, 1891-98, 1890, 1887-89, 1885, 1884, 1883, 1882, 1881, 1879-80, 1878, ?1874-75, 1872-73, 1870?, 1869, 1868, 1867, 1866, 1864-65, 1863, 1859-60, 1858-59,1857, 1856, 1854, 1850, 1844, 1842, 1838-40, 1836, 1825, 1817, 1805-07, 1802-03, 1798, 1793, 1783, 1772?, 1770.