Hualca Hualca forms a volcanic complex with the two southerly volcanoes
Sabancaya and
Ampato. It is older (
Pliocene-
Pleistocene) and more heavily eroded than these two volcanoes; they are all constructed on
Neogeneignimbrites, one of which was dated to 2.2 ± 1.5 million years ago.[15] The volcano has erupted andesitic lava flows; one series of such flows exceeds a thickness of 0.5 kilometres (0.31 mi).[16] Volcanic rocks of Hualca Hualca contain
phenocrysts of
biotite,
clinopyroxene,
hornblende,
orthopyroxene,
plagioclase and
sphene. The magma probably originated through mixing processes, similar to Sabancaya.[5]
Sector collapse
The northern flank of Hualca Hualca underwent a large sector collapse between 1.36 and 0.61 million years ago,[16] opening up a collapse amphitheatre[17] and forming a lake in the Colca valley which later catastrophically failed.[16] This lake has left lacustrine deposits in the Colca Valley.[18] Eruptions within the collapse amphitheatre generated
lava flows which then formed
volcanic dams in the Colca Valley.[19]Lava domes and
pyroclastic flows also originated within the collapse scar.[5] Earthquakes and hydrothermal alteration probably caused the onset of the collapse event.[18]
Glaciation
The volcano was glaciated during the
last ice age, between 18,000 and 11,500 years ago.[20] This glaciation has left
moraines,
rock glaciers and
roches moutonees.[18] The glaciers on Hualca Hualca have retreated since then, one was reported to have disappeared by 2000.[21]Snowmelt and
runoff from Hualca Hualca are sources of water for the
Colca Canyon, supporting
irrigated agriculture there; the mountain is worshipped by local inhabitants, who according to reports in 1586 believed that their ancestors come from it.[22]
Recent activity
Hualca Hualca is considered to be an extinct volcano;[14] however at least seven
vents on its southwestern flank show evidence of
Holocene activity.[18] Satellite images in the early 21st century found that Hualca Hualca is inflating from a depth of 13–11 kilometres (8.1–6.8 mi) at a rate of 2 centimetres per year (0.79 in/year). This
deformation may be associated with the neighbouring volcano
Sabancaya which is active;
magma chambers of volcanoes are sometimes distant from the actual volcano as was the case with
Katmai.[23] The inflation ceased after 1997.[24] At Pinchollo in the collapse scar three geysers were active in the past; one is still active as of 2013[update] and is named Infiernillo.[17] The activity of the
hydrothermal system at Hualca Hualca increased beginning in 2016, an increase linked to eruptions of Sabancaya and earthquakes.[25]
Climbing and first ascent
Hualca Hualca can be climbed in a few days from the village of Pinchollo by the north side.[26] It was first climbed by Richard R. Culbert from Canada on 6 April 1966. Evidence of
pre-Columbian ascents possibly from
Incans, such as
coca leaves and a
puma skin, was found near the summit. Some reports show Piero Ghiglione and P. Chavez reaching the summit on 23 August 1950, however this was a secondary summit.[1]
^
abcdBurkett, B. (1 December 2005). "Volcanism at Hualca Hualca Volcano, Southern Peru". AGU Fall Meeting Abstracts. 53: V53B–1552.
Bibcode:
2005AGUFM.V53B1552B.
^
abPeru 1:100 000, Chivay (32-s). IGN (Instituto Geográfico Nacional – Perú). as Nevado Hualca Hualca
^Radio San Gabriel, "Instituto Radiofonico de Promoción Aymara" (IRPA) 1993, Republicado por Instituto de las Lenguas y Literaturas Andinas-Amazónicas (ILLLA-A) 2011, Transcripción del Vocabulario de la Lengua Aymara, P.
Ludovico Bertonio 1612 (Spanish-Aymara-Aymara-Spanish dictionary)
^Gerbe, Marie-Christine; Thouret, Jean-Claude (1 August 2004). "Role of magma mixing in the petrogenesis of tephra erupted during the 1990–98 explosive activity of Nevado Sabancaya, southern Peru". Bulletin of Volcanology. 66 (6): 541–561.
doi:
10.1007/s00445-004-0340-3.
ISSN0258-8900.
S2CID128592747.
^Alcalá, Jesus; Palacios, David; Vazquez, Lorenzo; Juan Zamorano, Jose (1 April 2015). "Timing of maximum glacial extent and deglaciation from HualcaHualca volcano (southern Peru), obtained with cosmogenic 36Cl". EGU General Assembly Conference Abstracts. 17: 12930.
Bibcode:
2015EGUGA..1712930A.
^Alcalá, Jesus; Palacios, David; Juan Zamorano, Jose (1 April 2015). "Reconstruction of glacial changes on HualcaHualca volcano (southern Peru) from the Maximum Glacier Extent to present". EGU General Assembly Conference Abstracts. 17: 13492.
Bibcode:
2015EGUGA..1713492A.
^Boelens, Rutgerd; Gelles, Paul H. (1 July 2005). "Cultural Politics, Communal Resistance and Identity in Andean Irrigation Development". Bulletin of Latin American Research. 24 (3): 311–327.
doi:
10.1111/j.0261-3050.2005.00137.x.
ISSN1470-9856.