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40-476: Cotopaxi is known to have erupted 87 times, resulting in the creation of numerous valleys formed by lahars (mudflows) around the volcano. An ongoing eruption began on 21 October 2022. At the end of February 2023, the Geophysical Institute of Ecuador reported that Cotopaxi had produced around 8,000 earthquakes since October 21, 2022, amounting to 1,600 events per month. On a clear day, Cotopaxi

80-766: A potential path of more than 300 kilometres (190 mi). Lahars from the 1985 Nevado del Ruiz eruption in Colombia caused the Armero tragedy , burying the city of Armero under 5 metres (16 ft) of mud and debris and killing an estimated 23,000 people. A lahar caused New Zealand's Tangiwai disaster , where 151 people died after a Christmas Eve express train fell into the Whangaehu River in 1953. Lahars have caused 17% of volcano-related deaths between 1783 and 1997. Lahars have several possible causes: In particular, although lahars are typically associated with

120-521: A significant eruption of Cotopaxi would be the flash-melting of its summit glacier, resulting in devastating lahars which would travel down the flanks of the volcano, guided by river valleys whose origins lie at the volcano. Danger from normal, explosive eruptive activity is limited to within Cotopaxi National Park. However, the great distances that lahars of the significant size that Cotopaxi's glacier produces could travel greatly increase

160-557: A wall of mud 140 metres (460 ft) deep in the White River canyon and covered an area of over 330 square kilometres (130 sq mi), for a total volume of 2.3 cubic kilometres ( 1 ⁄ 2  cu mi). A debris-flow lahar can erase virtually any structure in its path, while a hyperconcentrated-flow lahar is capable of carving its own pathway, destroying buildings by undermining their foundations. A hyperconcentrated-flow lahar can leave even frail huts standing, while at

200-470: Is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano , typically along a river valley . Lahars are often extremely destructive and deadly; they can flow tens of metres per second, they have been known to be up to 140 metres (460 ft) deep, and large flows tend to destroy any structures in their path. Notable lahars include those at Mount Pinatubo in

240-526: Is clearly visible on the skyline from Latacunga and Quito . It is part of the chain of volcanoes around the Pacific Plate known as the Pacific Ring of Fire . It has an almost symmetrical cone that rises from a highland plain of about 3,800 m (12,470 ft), with a width at its base of about 23 km (14 mi). It has one of the few equatorial glaciers in the world, which starts at

280-581: The Philippine government were not adequate to stop over 6 m (20 ft) of mud from flooding many villages around Mount Pinatubo from 1992 through 1998. Scientists and governments try to identify areas with a high risk of lahars based on historical events and computer models . Volcano scientists play a critical role in effective hazard education by informing officials and the public about realistic hazard probabilities and scenarios (including potential magnitude, timing, and impacts); by helping evaluate

320-463: The Italian guides Jean-Antoine Carrel and Louis Carrel made the third recorded ascent of Cotopaxi and spent a night on the summit. Painters Rudolf Reschreiter and Hans Meyer reached the summit in 1903, and many of Reschreiter's paintings feature a view of Cotopaxi. In the late 20th century, summiting Cotopaxi became a major tourist draw. The José F. Ribas Refuge ( Refugio José Félix Ribas )

360-746: The Philippines and Nevado del Ruiz in Colombia, the latter of which killed more than 20,000 people in the Armero tragedy . The word lahar is of Javanese origin. Berend George Escher introduced it as a geological term in 1922. The word lahar is a general term for a flowing mixture of water and pyroclastic debris. It does not refer to a particular rheology or sediment concentration. Lahars can occur as normal stream flows (sediment concentration of less than 30%), hyper-concentrated stream flows (sediment concentration between 30 and 60%), or debris flows (sediment concentration exceeding 60%). Indeed,

400-520: The Philippines in 2006. Moritz Alphons St%C3%BCbel Moritz Alphons Stübel (26 July 1835 – 10 November 1904) was a German geologist and naturalist . He studied chemistry and mineralogy at the University of Leipzig . With geologist Wilhelm Reiss (1838–1908), he conducted geological and volcanological research in the Andes—Colombia and Ecuador—from 1868 to 1874. Afterwards

440-571: The Ribas Refuge is under construction. Tour operators shuttle their clients up to the top of the 4WD track once in the afternoon for a glacier skills class, and then again to start the climb around midnight, spending the intervening hours eating dinner and resting at a hostel lower down by the lakes. Adventure tourism operators in Quito also offer mountain biking tours from the Refuge downhill along

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480-453: The crevasses. A 4WD track goes up from the national park entrance to a carpark at 4,600 m (15,100 ft) altitude on north side, just below the José F. Ribas Refuge. This stone mountain hut — owned and operated by Grupo Ascensionismo del Colegio San Gabriel — is situated 200 m (660 ft) higher at 4,800 m (15,700 ft) (a 40-80 minute uphill hike). Here climbers can spend

520-430: The dirt track. In April 2015, the volcano began to show signs of unrest, and came back to life. There was a large increase in earthquakes (including harmonic tremors ) and SO 2 emissions. IGEPN reported slight deformation of the edifice, suggesting an intrusion of magma under the volcano. As of 25 July, the unrest continued, and a significant eruption of phreatic ash and steam occurred on August 14 and 15, 2015. Ash

560-557: The effectiveness of proposed risk-reduction strategies; by helping promote acceptance of (and confidence in) hazards information through participatory engagement with officials and vulnerable communities as partners in risk reduction efforts; and by communicating with emergency managers during extreme events. An example of such a model is TITAN2D . These models are directed towards future planning: identifying low-risk regions to place community buildings, discovering how to mitigate lahars with dams, and constructing evacuation plans. In 1985,

600-612: The effects of volcanic activity, lahars can occur even without any current volcanic activity, as long as the conditions are right to cause the collapse and movement of mud originating from existing volcanic ash deposits. Several mountains in the world – including Mount Rainier in the United States, Mount Ruapehu in New Zealand, and Merapi and Galunggung in Indonesia – are considered particularly dangerous due to

640-894: The event of a Mount Rainier eruption. A lahar warning system has been set up at Mount Ruapehu by the New Zealand Department of Conservation and hailed as a success after it successfully alerted officials to an impending lahar on 18 March 2007. Since mid-June 1991, when violent eruptions triggered Mount Pinatubo 's first lahars in 500 years, a system to monitor and warn of lahars has been in operation. Radio-telemetered rain gauges provide data on rainfall in lahar source regions, acoustic flow monitors on stream banks detect ground vibration as lahars pass, and staffed watchpoints further confirm that lahars are rushing down Pinatubo's slopes. This system has enabled warnings to be sounded for most but not all major lahars at Pinatubo, saving hundreds of lives. Physical preventative measures by

680-432: The guarantor of the land's fertility, and at the same time its summit was revered as a place where gods lived. With 87 known eruptions, Cotopaxi is one of Ecuador's most active volcanoes. Its first recorded eruption was in 1534. This eruption appears to have deposited an ash layer in the lakes of El Cajas National Park that has been dated to 450±70 cal BP. Cotopaxi's most violent eruptions in historical times occurred in

720-535: The hazard areas to include all river valleys leading from the volcano. If there were to be a very large explosion, it would destroy many northerly settlements within the valley in the suburban area of Quito (pop. more than 2,000,000). Another city which would be in great danger is the regional capital Latacunga , which is located in the south valley, and has been destroyed at least twice (in 1768, 1877) by lahars caused by volcanic activity. Lahar A lahar ( / ˈ l ɑː h ɑːr / , from Javanese : ꦮ꧀ꦭꦲꦂ )

760-696: The heart of the city and surrounding areas. Over 6 metres (20 ft) of mud inundated and damaged the towns of Castillejos , San Marcelino and Botolan in Zambales , Porac and Mabalacat in Pampanga , Tarlac City , Capas , Concepcion and Bamban in Tarlac . The Bamban Bridge on the MacArthur Highway, a major north–south transportation route, was destroyed, and temporary bridges erected in its place were inundated by subsequent lahars. On

800-401: The height of 5,000 m (16,400 ft). At its summit, Cotopaxi has an 800 m × 550 m (2,620 ft × 1,800 ft) wide crater which is 250 m (820 ft) deep. The crater consists of two concentric crater rims, the outer one being partly free of snow and irregular in shape. The crater interior is covered with ice cornices and rather flat. The highest point is on

840-442: The ice wall broke loose. Being Easter, there were many day visitors on the mountain who were buried in the ice and snow. Those trapped in the Refuge broke windows on the downhill side to climb to safety, but 13 people died on the slope above. The Refuge itself is located in a valley and consequently vulnerable to future avalanches. Climbing Cotopaxi to the summit is quite popular, with up to 100 climbers attempting it on weekends. When

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880-480: The lahars killed more than 1500. The eye of Typhoon Yunya passed over the volcano during its eruption on 15 June 1991, and the resulting rain triggered the flow of volcanic ash , boulders, and water down rivers surrounding the volcano. Angeles City in Pampanga and neighbouring cities and towns were damaged by lahars when Sapang Balen Creek and the Abacan River became channels for mudflows and carried them to

920-676: The morning of 1 October 1995, pyroclastic material which clung to the slopes of Pinatubo and surrounding mountains rushed down because of heavy rain, and turned into an 8-metre (25 ft) lahar. This mudflow killed at least 100 people in Barangay Cabalantian in Bacolor . The Philippine government under President Fidel V. Ramos ordered the construction of the FVR Mega Dike in an attempt to protect people from further mudflows. Typhoon Reming triggered additional lahars in

960-478: The morning of August 14 marked a new phase of volcanic activity. The volcano "remains in a very abnormal situation. In August, 2,100 earthquakes were recorded and emission rates of sulfur dioxide reach approximately 20,000 tonnes per day (19,700 long ton/d; 22,000 short ton/d). The government estimates some 300,000 people are at risk from the volcano in the provinces of Cotopaxi, Tungurahua, Napo and Pichincha. The first non-Spanish European who tried to climb

1000-566: The mountain was Alexander von Humboldt in 1802; however, he only reached a height of about 4,500 m (14,760 ft). In 1858 Moritz Wagner investigated the mountain, but he could not reach the summit either. On November 28, 1872, German geologist Wilhelm Reiss and his Colombian partner, Angel Escobar, finally reached the summit of Cotopaxi. In 1873 it was summitted by German Geologist Moritz Alphons Stübel and four Ecuadorians, Rafael Jantui, Melchor Páez, Vicente Ramón and Eusebio Rodriguez. In 1880 British mountaineer Edward Whymper and

1040-520: The mudslide deposits. The eruption on 19 June 1742 was witnessed by the scientists Pierre Bouguer and Charles-Marie de La Condamine , members of the French Geodesic Mission , as they descended from nearby Guagua Pichincha . There was a major eruption from 1903 to 1904, and minor activity persisted until at least 1940 and possibly 1942. (Note that direct observations of minor eruptions can be difficult because of bad weather, hence

1080-430: The night and begin their summit bid in the early morning without any intermediate camps. (Typically no more than about half of those attempting to summit Cotopaxi make it to the top after a daunting — though non-technical — six-hour scramble.) Summiting normally starts around 12:30 am, to reach the summit at latest 7:30 am and then return to the hut before the snow melts and glacier crevasses move/evolve. As of July 28, 2014,

1120-479: The outer rim of the crater on the north side. According to locals who speak Quechua , coto means 'neck' and paxi means 'moon' (Quechua q'oto 'throat' + Aymara phakhsi 'moon'). This refers to the crater of Cotopaxi that looks like a crescent moon. The mountain was honored as a sacred mountain by local Andean people, even before the Inca invasion in the 15th century. It was worshiped as rain sender, which served as

1160-529: The overall death toll to over 25,000. Footage and photographs of Omayra Sánchez , a young victim of the tragedy , were published around the world. Other photographs of the lahars and the impact of the disaster captured attention worldwide and led to controversy over the degree to which the Colombian government was responsible for the disaster. Lahars caused most of the deaths of the 1991 eruption of Mount Pinatubo . The initial eruption killed six people, but

1200-640: The rheology and subsequent behaviour of a lahar may vary in place and time within a single event, owing to changes in sediment supply and water supply. Lahars are described as 'primary' or 'syn-eruptive' if they occur simultaneously with or are triggered by primary volcanic activity. 'Secondary' or 'post-eruptive' lahars occur in the absence of primary volcanic activity, e.g. as a result of rainfall during pauses in activity or during dormancy. In addition to their variable rheology, lahars vary considerably in magnitude. The Osceola Lahar produced by Mount Rainier in modern-day Washington some 5600 years ago resulted in

1240-706: The risk of lahars. Several towns in the Puyallup River valley in Washington state, including Orting , are built on top of lahar deposits that are only about 500 years old. Lahars are predicted to flow through the valley every 500 to 1,000 years, so Orting, Sumner , Puyallup , Fife , and the Port of Tacoma face considerable risk. The USGS has set up lahar warning sirens in Pierce County, Washington , so that people can flee an approaching debris flow in

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1280-691: The same time burying them in mud, which can harden to near-concrete hardness. A lahar's viscosity decreases the longer it flows and can be further thinned by rain, producing a quicksand -like mixture that can remain fluidized for weeks and complicate search and rescue. Lahars vary in speed. Small lahars less than a few metres wide and several centimetres deep may flow a few metres per second. Large lahars hundreds of metres wide and tens of metres deep can flow several tens of metres per second (22 mph or more), much too fast for people to outrun. On steep slopes, lahar speeds can exceed 200 kilometres per hour (120 mph). A lahar can cause catastrophic destruction along

1320-431: The summit is quiet, mountain guide companies offer regular guided climbs of the mountain. Climbers grade the conventional route alpine PD (Peu Difficile) or WS (Wenig Schwierig) — or PD/WS+ (indicating "Mildly Difficult PLUS"). Use of crampons and ice axes is mandatory as snow and ice slopes of up to 50 degrees (1 in 2) are encountered, and climbers should be on belay and use aluminum ladders to cross one or two of

1360-627: The two geologists continued their research in Peru and Brazil, with Reiss returning to Germany in 1876 and Stübel continuing his travels throughout the continent: Uruguay, Argentina, Chile and Bolivia – returning to Germany in August ;1877. In South America, he also made astronomical measurements and performed meteorological , ethnographical , zoological , and archaeological research. Scientific material collected in South America

1400-408: The uncertainty about the 1942 "eruption.") The same source also reported increased thermal/seismic, non-eruptive activity in 1975 and 2002. In the increased activity of 2002, fumarolic activity and sulfuric emissions increased and ice around the inside and on the southeastern side of the cone started to melt. However, no actual eruption was observed. In 2015, two large phreatic (steam) eruptions on

1440-517: The volcano Nevado del Ruiz erupted in central Colombia. As pyroclastic flows erupted from the volcano's crater , they melted the mountain's glaciers, sending four enormous lahars down its slopes at 60 kilometers per hour (37 miles per hour). The lahars picked up speed in gullies and coursed into the six major rivers at the base of the volcano; they engulfed the town of Armero , killing more than 20,000 of its almost 29,000 inhabitants. Casualties in other towns, particularly Chinchiná , brought

1480-533: The years 1742, 1744, 1768, and 1877. The 1744 and 1768 events destroyed the colonial town of Latacunga . During the June 26, 1877 eruption, pyroclastic flows descended on all sides of the mountain melting the entire ice cap, with lahars traveling more than 100 km (62 mi) into the Pacific Ocean and western Amazon basin draining the valley. The city of Latacunga was again leveled completely due to

1520-401: Was built in 1971 at an elevation of 4,864 m (15,960 ft) and enlarged in 2005. A tragedy occurred on Easter Sunday 1996 when an avalanche partially buried the Refuge and dozens of tourists. The glacier above the Refuge was probably weakened by an earthquake that had shaken the entire Province of Cotopaxi for several days prior to the avalanche. In the warm midday sun a huge portion of

1560-413: Was deposited heavily in areas close to the volcano, including damaging farmlands on the flanks of neighbouring volcanoes such as El Corazon, and thinly as far as Quito, affecting southern and central areas of the city. A new eruption began on 21 October 2022 and is ongoing as of June 2023. Future Cotopaxi eruptions pose a high risk to the local population, their settlements and fields. The main danger of

1600-852: Was later preserved at the Museum of Comparative Cultures in Leipzig. In addition, Stübel took numerous photographs and created sketches of the places he visited. Many of the butterflies collected by Stübel were new species. They were described by German entomologists Gustav Weymer and Peter Maassen . Stübel also made a lesser known contribution to the study of the Middle East. In the years 1858, 1882, and 1890, he traveled mainly in Syria, Lebanon, Palestine , and Egypt. He collected about 600 large-size photographs on these journeys and at other occasions. This collection came via his nephew, Bruno Stübel, to

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