1. Christy Adler & Sarah Carrigan Department of Geology, Colby College
Ubinas, Peru
Here’s a picture of the volcano in 2014

2. Geographic and Tectonic Setting
Southern Peru, °S, °W
Pacific Ring of Fire
Nazca Plate Volcanoes, Andes Mountain Range
470 miles southeast of Lima
Most active volcano in Peru
-Mount Ubinas is located in Southern Peru
-Mount Ubinas is along the Pacific Ring of Fire, where the Nazca Plate is subducting under the South American Plate
-It is a part of the Andes Mountain Range, which extends along the Western Coast of South America
-it is located 470 miles Southeast of Lima, 40 miles East of Arequipa, where the a volcano observatory is located.
-Mount Ubinas is actually the second Volcano in its place. Ubinas I was the original volcano, which was destroyed and replaced by Ubinas II in the Mid-Pleistocene Era

3. Form and Dimensions of Ubinas
Elevation: 18,609 ft.
Summit: 5,672 m.
Quasi-symmetrical, cone-shaped
Upper slopes: 45 degrees
Stratovolcano & composite volcano
Andesitic and Rhyolitic
Upper slopes: made up primarily of Pleistocene andesitic lava flows
Its composition is andesitic and rhyolitic

4. Vents, Craters, Calderas… oh my!
Caldera: 1.4 km wide and 105 m deep
Ash cone: in the center of the caldera
Vent: 500 m wide, funnel shaped
SE flank collapsed 3700 years ago, extends 10 km out
-Mount Ubinas has a Caldera on the summit, which is apx. 1.5 kilometers wide, and a little over 100 meters deep
-In the center of the Caldera is a small Ash Cone which is 500 m wide
- The Caldera also contains a vent, which is funnel shaped.
-The SouthEastern flank of the volcano collapsed 3700 years ago, and resulted in a pyroclastic flow for 10 km out

5. Eruptive History
2014
1867
1865
1862
1969
1830
1956
1826
1951
1784
1937
1677
1907
1662
1906
1600
1869
1550
Intermittent small to medium eruptions (“calm and strong eruptions”)
Most eruptions consist of ash and steam emissions
20 eruptions in past 500 years
Recently, it has erupted approximately 6-7 times per century
map shows boundary of Ubinas ashfall
most eruptions consist of ash and steam emissions
examples:
1956: eruption damaged crops and livestock up to 6 km southeast of Ubinas
1667: largest known eruption in Ubinas’ history (volcanic explosivity index of 4, and it produced 0.1 cubic km of lava flows)

6. Observed Eruptions Nov 2014 - Mostly ash, 2 explosions
March Residents evacuated
April Residents evacuated, complaints of head and stomachaches
Images from Guido Salas, Facultad de Geologia y Geofisica, Universidad Nacional de San Agustin, Arequipa, Peru
Mount Ubinas has had several significant eruptions in the past few years.
The latest eruption ended in November 2014, a little over 2 months ago. This eruption consisted mostly of ash and a couple of explosions.
The eruption started earlier in 2014, and even caused nearby residents to be evacuated in March 2014
Another eruption took place in 2006 and consisted of 3 major stages. The first, in late 2005, consisted only of gas. The second stage was a combination of ash and gas. The eruption culminated in a moderate explosion and lava bombs in April The explosions also resulted in a lava dome forming near the crater. These explosions in 2006 resulted in the evacuation of the city of Querapi, where citizens began complaining of headaches and stomachaches. Continued eruptions caused a larger parameter to be evacuated in May 2006.

7. 2006 image from the International Space Station
(NASA Earth Observatory)
This is a photo from the 2006 eruption from the NASA Earth Observatory

8. Volcanic Hazards & Contributions
Biggest Issue: Ash
Another Issue: Pyroclastic Flows
Population:
w/in 5 m - 180
w/in 10 km
w/in 30 km - 14,607
w/in 100 km - 1,136,785
ASH:
Ash accumulates and kills crops and livestock, affects local economies, causes respiratory and skin problems
In the first image, authorities are handing out gas masks and protective glasses
1956 Eruption: Ash eruptions killed crops and livestock in the Ubinas Villages
2006 Eruption: Ash accumulation of 1.5 cm in Querapi (4.5 km away)
Peru’s National Water Authority: monitors the water in the Ubinas area to make sure it’s safe for consumption
FLOWS
Pyroclastic Flow pathways are to the SE side of the volcano. Unfortunately, this is where many people have settled. The town of Querpi is in this area
POPULATION:
It’s not very population very close to the volcano, but the people further away could also be in danger

9. Rocks and Deposits Rock Types (Petrology): andesite/basaltic andesite
dacite
rhyolite
melted Nazca Plate
Volcanic Deposits:
Plinian pumice falls
Form:
Pyroclastic cone
Caldera
Holocene Lava Flows and Pyroclastic Flows
Younger lava flows on western flanks
The volcanic deposits consist largely of Plinian pumice falls, resulting from large explosive eruptions.

10. Geophysical and Active Monitoring
Geophysical Institute of Peru
Institut de Recherche pour le Développment (France)
2012: built a seismic network around the volcano
April 2014:
rising magma detected in the dome
the team advised the nearby town of Querapi to evacuate
“The final aim is to introduce this kind of analysis as quantitative tools to understand ongoing eruptive phases at andesitic volcanoes and possibly to forecast magma/fluid significant movements.”
April 2014:
state of emergency declared

11. Tourism
Mt. Ubinas is also the center of a large amount of tourism. Besides the beautiful surroundings, when not in an eruptive state, Mt. Ubinas is a center large hiking and mountaineering. Tourists can pay $295 to hire a local tour guide and hike to the top!

12. Bibliography
Baral, S., 2014: Peru Volcano Erupts After 40 Year: 4 Fast Facts About Mount Ubinas’ Eruption, at (accessed January 20, 2015)
Global Volcanism Program, Smithsonian Institution, 2013: Ubinas, at (accessed January 20, 2015)
Ooska News, May 1, 2014: Peru's National Water Authority Monitoring Water Quality in Wake of Ubinas Volcanic Eruption, at
(accessed January 20, 2015)
Oregon State University, (n.d.): Structure and Evolution, at (accessed January 23, 2015)
Peru Adventure Tours, (n.d.): Ubinas Volcano; High Trekking To The Most Active Volcano of the Andes, at
(accessed January 20, 2015)
Seach, J., 2014: Volcano Live: Ubinas Volcano, at (accessed January 23, 2015)
Summit Post, 2014: Volcán Ubinas, at (accessed January 20, 2015)
Volcano Discovery, 2014: Ubinas Volcano, at (accessed January 20, 2015).
Zandomeneghi, D., Inza, A., & Macedo, O., 2012:. Long-Period seismic events at Ubinas Volcano (Peru): Their implications and potentiality as monitoring
tool at (accessed January 20, 2015)