Hualālai last erupted in 1801. A severe earthquake swarm shook the volcano in 1929, lasting about a month. This caused $100,000 worth of damage to the Kona district ($1.2 million as of 2010), and two earthquakes with magnitudes of 5.5 and 6.5 were felt as far away as Honolulu. This was probably caused by magma movement near the surface, but there was no surface activity or eruption. The 2006 Kiholo Bay earthquake, with epicenter just to the north in Kiholo Bay near Māhukona, caused much damage in the area.
Recent activity
Hualālai
Hualālai | Recent activity
The 2006 Kiholo Bay earthquake. Hualālai is estimated to have risen above sea level about 300,000 years ago. Despite maintaining a very low level of activity since its last eruption in 1801 he 2006 Kiholo Bay earthquake, with epicenter just to the north in Kiholo Bay near Māhukona, caused much damage in the area Sorry. I cannot find the answer based on the context.
when was the last time mauna loa volcano erupted
user
March 24 to April 15, 1984.
assistant
what is the main entity?
user
It is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaiʻi in the Pacific Ocean.
assistant
what is its weather like?
user
It has a tropical climate with warm temperatures at lower elevations and cool to cold temperatures higher up year-round.
assistant
who monitors this volcano?
user
The Hawaiian Volcano Observatory, a branch of the United States Geological Survey.
assistant
who founded it ?
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Thomas A. Jaggar.
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where is it located?
user
A temporary offices located in Hilo on the Island of Hawaii.
assistant
mention few volcanoes it monitors?
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Kīlauea, Mauna Loa, Hualālai, and Haleakalā.
assistant
name few dangers of the second?
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It is a sudden, massive collapse of the volcano's flanks,  large earthquakes could trigger rapid flank collapses along these lines, creating massive landslides and possibly triggering equally large tsunamis.
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any recent updates seen in the third?
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Hualālai is the third most active volcano making up the island of Hawaii, behind Kīlauea and Mauna Loa. Although the two larger volcanos have each erupted over 150 times in the last 1,000 years, Hualālai has done so but 3 times. The recurrence of activity at the volcano seems to be every 200 to 300 years. A recent calm period, with almost no earthquake or magmatic activity at Hualālai, has seen the growth of homes, businesses, and resorts on the mountain's flanks. The most recent major activity at the volcano was in 1929, when an intense earthquake swarm rocked Hualālai, most likely caused by magmatic action near the volcano's peak.
Hualālai | Eruption history
Although it has been relatively placid in the recent past, Hualālai is still potentially active, and is expected to erupt again within the next 100 years.
Hualālai | Eruption history
Hualālai is expected to erupt again in the near future, as a 200- to 300-year estimated pause in activity is coming to an end. This presents a distinct hazard to the communities around it as well; for example, in the event of an eruption similar to the 1801 event, Kailua-Kona, which is from the volcano's summit, could be covered completely in a matter of hours. According to the USGS lava-flow hazard zones, on a scale of 1 to 9, all of Hualālai is listed as threat level 4. For comparison, almost all of Kīlauea and Mauna Loa is listed as threat levels 1 through 3.
Hualālai | Future monitoring
The flanks of the volcano do not pose a lower threat to the population than the area near the rift zones because the distance is short and the slopes are steep; lava poses as much of a threat as it does near its source. Since 1991, the Hawaiian Volcano Observatory (HVO) has maintained a seismic recording station east of Hualālai's summit to monitor the volcano. During this time, not a single earthquake swarm or harmonic tremor, indicative of activity at the volcano, has occurred. Although Hualālai does experience several magnitude-4 earthquakes per year, these are attributed to a deep source off the coast of the north-western rift zone and are not related to the movement of magma.
Hualālai | Future monitoring
Hualālai last erupted in 1801. A severe earthquake swarm shook the volcano in 1929, lasting about a month. This caused $100,000 worth of damage to the Kona district ($1.2 million as of 2010), and two earthquakes with magnitudes of 5.5 and 6.5 were felt as far away as Honolulu. This was probably caused by magma movement near the surface, but there was no surface activity or eruption. The 2006 Kiholo Bay earthquake, with epicenter just to the north in Kiholo Bay near Māhukona, caused much damage in the area.
Hualālai | Recent activity
The post-collapse lava flows have been affected by glacial activity, indicating that eruptive activity ceased before the end of the last glacial stage; thus the volcano was largely constructed in pre-Holocene times. However, a long and wide lava flow extending from the youngest summit lava dome appears to post-date glaciation, and the dome itself is also unmodified. An uncertain report of an eruption on 3 December 1903 exists, as well as on 8 October 1927. Increased fumarolic activity was observed in 1854, 1888, 1889, and 1960. Substantial earthquake activity occurs at Ollagüe in a diffuse pattern around the volcano, sometimes in the form of seismic swarms.
Ollagüe | Recent activity and hazards
The resulting debris-avalanche deposit covers an eighty km area to the northeast, although much of soils all around contain volcanic residues. The last known eruption occurred about 700 years ago, but there is still a possibility of it reactivating and should be monitored. The volcano is part of an ecological reserve as part of the Isidro Fabela State Park. On the road that leads up the volcano, there is a statue of the Virgin Mary. This road leads to a lookout point at the top, which allows for a view of about forty km in all directions. Visible from the valley floor are the radio and television transmission towers that are at the top.
Jocotitlán | Geography and environment
Scientists flying over the volcano on March 8, 2012 noted fresh ash deposits on the east flank of the volcano near the crater, likely from an phreatic eruption on February 22. Later that day, a small ash plume erupted from the crater; by March 13, scientists detected ash deposits at the head of the Gualí River. After seismicity continued to increase, the alert level was raised to Orange, and in April Nevados National Natural Park authority closed the reserve, fearing lahars and ashfall hazards. The sudden activity peak in March did not culminate in a major eruption, and activity declined enough that the alert level was lowered to Yellow on May 3.
Nevado del Ruiz | Recent activity
Much of the north side and a large part of the center of the city was destroyed in 1941 by floodwaters and avalanche debris because of a burst reservoir from Lake Palcacocha that was the city's municipal water supply. The reservoir dam was about east of the town and more than 200 meters elevation above it. The dam failed because of sudden overflow pressure from an avalanche of glacier ice probably caused by a localized tremor (earthquake). Within a few minutes the stream bed was filled with an avalanche of water, mud, boulders, and associated debris whose crest by the time it reached the city may have exceeded 15 meters height above the stream bed.
Huaraz | Contemporary times
The first is the formation of long debris avalanches or pyroclastic flows that could reach the which is just away from the volcano. The second hazard is formed by a large explosive eruption resulting in ash fall and the emplacement of ignimbrites; the whole region could be affected if the eruption column is over high. A few seismic stations monitor earthquake activity at San Pedro. The Chilean SERNAGEOMIN publishes a volcano hazard level for the volcano.
San Pedro (Chile volcano) | Historical activity
Within its duration of 45 seconds, virtually every structure of consequence in the city's center was destroyed. A few minutes later, the north half of the city, particularly in the creek valley, was obliterated by an avalanche of icy mud carrying boulders and other debris.
Huaraz | Contemporary times
In late 2012 the mountain became quite active, spewing volcanic ash. In November 2012, and continuing into 2013, a 3 km exclusion zone was set up and residents living around the mountain were evacuated or moved to Maumere city on the main island of Flores. In the first 8 months of 2013 there was regular activity from the lava dome including repeated ash plumes – generally reaching altitudes of 2–3 km – dome collapses, explosions, avalanches and pyroclastic flows.
Paluweh | 2012–2013
In 2000, after a long period of quiescence, the volcano entered an eruptive phase that continues to this day (). The renewed activity in October 1999 produced major ashfall and led to the temporary evacuation of more than 25,000 inhabitants from Baños and the surrounding area Activity continued at a medium level until May 2006, when activity increased dramatically, culminating in violent eruptions on 14 July 2006 and 16 August 2006. The 16 August 2006 eruption has been the most violent since activity commenced in 1999. This eruption was accompanied by a high ash plume which spread over an area of , depositing ash and tephra to the southwest of the volcano.
Tungurahua | Recent volcanic activity
After a hiatus the volcano began erupting pyroclastic flows, which were mostly constrained by the topography and were erupted in various stages interrupted by ash fall that extended to larger distances. Most of these pyroclastic flows accumulated in valleys radiating away from Huaynaputina, the flows reaching distances of from the vents. Winds blew ash from the pyroclastic flows, and rain eroded freshly emplaced pyroclastic deposits. Ash fall and pyroclastic flows alternated during this stage, probably caused by brief obstructions of the vent; at this time a lava dome formed within the second vent. A change in the composition of the erupted rocks occurred, with the "Dacite 1" geochemical suite being increasingly modified by the "Dacite 2" geochemical suite that became dominant during the third stage.
Huaynaputina | Second pyroclastic stage
Several pyroclastic flows were generated that killed at least five people, and destroyed a number of hamlets and roads on the eastern and northwestern slopes of the volcano. A further eruption and evacuation occurred on 4 December 2010. Ecuador's National Agency of Risk Control issued a "red alert", later downgraded to orange. The Ecuadorean Institute for Geophysics reported a rapid increase in seismic activity, a number of explosions and an ash cloud reaching in height. Another eruption occurred on 18 December 2012 forcing evacuation of those living on the volcano's slopes. The volcano erupted again in July 2013. On 1 February 2014, the volcano erupted again.
Tungurahua | Recent volcanic activity
On May 29, seismicity rapidly increased, and the alert level was restored to Orange because ash fell into more than 20 nearby communities. Over the next few months ash fell frequently until earthquakes increased again in June. Because of the severity of these tremors, evacuations were ordered by the Emergency Committee of Caldas on news media for 300–1500 people near the volcano. The alert level was raised to Red, indicating an imminent major volcanic event, and an eruption in diameter took place on July 2, 2012, continuing intermittently until the end of August. Ash plumes and sulfur dioxide emissions recurred until January 2013.
Nevado del Ruiz | Recent activity
This area was explored more closely in a 2001 joint Japan-United States project to explore the volcano's flanks, utilizing the remotely operated vehicle ROV "Kaikō". Data collected showed that the lava flows there originated in shallow water deep, and that unlike similar slumps at other volcanoes, the slump at Hualālai formed gradually.
Hualālai | Structural features
However, the provincial government made efforts to prevent the news from spreading and urged people not to panic. The 1970 earthquake destabilized a glacier and snowmass which surged rapidly downhill, becoming a mudflow as it accumulated large volumes of loose dirt, rock and surface water. The death toll was made worse due to the earthquake having occurred on a Sunday, as thousands more people had congregated in Yungay for market when the mudflow struck and leveled the city. The slide then entered the Río Santa and caused extensive damage as it flowed all the way downstream to the Pacific Ocean.
1970 Huascarán debris avalanche | Introduction
More than half of this is under 3,000 years old, and about 12% is less than 1,000 years of age. Between the years 1700 and 2016, eruptions originated from six vents; four of these lava flows poured into the sea to the west coast.
Hualālai | History
Afterwards, collapses in the amphitheatre and within the vent enlarged both features and impeded further eruptive activity. A first pyroclastic flow was emplaced already during this time when the column became unstable. This stage was channelled by a fracture and had the characteristics of a fissure-fed eruption. Possibly, the second vent formed during this stage, but another interpretation is that the second vent is actually a collapse structure that formed late during the eruption. Much of the excavation of the conduit took place during this stage.
Huaynaputina | First Plinian stage
As of January 2013, Seulawah Agam is showing signs of renewed activity. Localised seismicity has been recorded in the vicinity of the volcano.
Seulawah Agam | Introduction
The second and probably also the third stage were subject to glacial erosion, which together with later sector collapses resulted in the removal of much of Taapaca's edifice and the exposure of the core of the volcano.
Taapaca | Phases
The substantial ice body in the caldera means that there is a significant risk of mudflows or glacier bursts in the case of renewed activity. Conversely, a retreat of the caldera-filling glacier might facilitate the onset of explosive eruptions at Sollipulli. A repeat of the Alpehué eruption would be a regional catastrophe, comparable to the 1991 eruption of Cerro Hudson volcano. The Chilean geological service Sernageomin monitors the volcano and publishes a hazard index for it. The towns of Cunco, Melipeuco and Villa García are close to the volcano. Melipeuco has devised a Volcanic Emergency Plan to deal with future eruptions of Llaima or Sollipulli.
Sollipulli | Hazards
Pyroclastic flows ran down the slopes of the volcano, entered the Río Tambo valley and formed dams on the river's course, probably mainly at the mouth of the Quebrada Aguas Blancas; one of the two dammed lakes was about long. When the dams failed, the lakes released hot water with floating pumice and debris down the Río Tambo. The deposits permanently altered the course of the river. The volume of the ignimbrites has been estimated to be about , without counting the ash that was erupted during this stage, and the pyroclastic flows along with pumice falls covered an area of about .
Huaynaputina | Second pyroclastic stage
The volcano continues to pose a serious threat to nearby towns and villages. The most likely hazard is small-volume eruptions, which might destabilize glaciers and trigger lahars. Despite the significant retrenchment of the volcano's glaciers, the volume of ice atop Nevado del Ruiz and other volcanoes in the Ruiz–Tolima massif remains large. Melting merely 10% of the ice would produce mudflows with a volume of up to —similar to the mudflow that destroyed Armero in 1985. Such lahars can travel up to along river valleys in a matter of few hours. Estimates show that up to 500,000 people living in the Combeima, Chinchiná, Coello-Toche, and Guali valleys are in danger, and 100,000 of these are considered to be at high risk.
Nevado del Ruiz | Current threats and preparedness
In 2010, earthquake activity and noises from Huaynaputina alerted the local population and led to a volcanological investigation. As part of this investigation, seismic activity was recorded around the amphitheatre; analysis showed that seismic activity was concentrated around the amphitheatre with no recorded earthquakes within it and appeared to be associated mainly with the faults and lineaments in the region. The researchers recommended more extensive seismometer coverage of the area and regular sampling of fumaroles, as well as reconnaissance of georadar and self potential of the volcano.
Huaynaputina | Hazards and volcanological research
After the disaster on 22 December, the volcanic activity of Anak Krakatau skyrocketed. A massive eruption occurred on 26 December and the sound of the eruption was noticeably heard by residents in Cianjur, West Java and Ogan Komering Ulu, South Sumatra, which was located more than 200 km from the volcano. Most people compared the sound of the eruption to a bomb blast or gas tank explosion. The Indonesian Meteorology, Climatology, and Geophysical Agency (BMKG) stated that sensors would be installed around the volcano and that the volcano would be observed intensively due to its unstable condition. On 27 December, the status of the volcano was raised to Level 3, the second highest danger level.
2018 Sunda Strait tsunami | Rising volcanic activity
Current movement of the Hilina slump and recent volcanic activity, coupled with evidence of massive submarine slides in the geological past, has led to sensationalistic claims of megatsunamis that might result if the south flank of Kīlauea should suddenly fail. Geologists are confident no such failure is likely, and other experts have stated that the supposed threats of megatsunamis are exaggerated.
Hilina Slump | Introduction
Tiltmeters installed on the volcano's north side displayed a northwest trending tilt for that side of the mountain, and a southwest trending tilt was observed on the south side. Worried that the amount of pressure on the magma underground was increasing, scientists analyzed gases by the crater, and found high traces of sulfur dioxide. After this discovery, they began to regularly check the fumarolic activity and monitor the volcano for dramatic changes, but none were observed. Disheartened, they instead opted to study the growing bulge and the threat an avalanche could have for humans relatively near the volcano. An evaluation of the threat was carried out, concluding that a landslide or avalanche in the Toutle River could spawn lahars, or mudflows, downstream.
David A. Johnston | Final signs and primary blast
However, the second phase of Eyjafjallajökull's eruption lasted longer than that of Mount Pinatubo.
2010 eruptions of Eyjafjallajökull | Comparison to other recent eruptions
Lava attributed to a shield-stage Hualālai has been found just offshore of the volcano's northwest rift zone. Tholeiitic basalt, indicative of the submarine subphase of the volcano's construction, has been found in wells driven into the volcano at a depth of . These lavas persisted until an estimated 130,000 years ago. Hualālai entered the post-shield stage, the stage it is presently in, about 100,000 years ago. Pumice and trachyte eruptions at Puu Waawaa may be a sign of this change. Geological mapping of the volcano has indicated that as much as 80% of the volcano's surface has been topped by lava flows during the last 5,000 years, entirely composed of shield alkalic basalt.
Hualālai | History
The second flow was basaltic in nature and marks the most recent activity of the volcano. The flow was dated using radiometric methods. Observers have reported minor activity at Sanford, primarily vapor clouds or plumes from ice and rockfalls. Some reported incidents may have been orographic clouds, while others have been interpreted as avalanches.
Mount Sanford (Alaska) | Geology
Deposits from the 1600 eruption and previous events also crop out within the amphitheatre walls. Another southeastward-opening landslide scar lies just north of Huaynaputina. One of these funnel-shaped vents is a trough that cuts into the amphitheatre, which appears to be a remnant of a fissure vent. The second appears to have been about wide before the development of the third vent, which has mostly obscured the first two. The third vent is steep-walled, with a depth of , and contains a wide pit within a small mound that is in part nested within the second vent. This third vent is surrounded by concentric faults, and at least one of the vents has been described as an ash cone.
Huaynaputina | Structure
In late October 2010 the Center for Volcanology and Geological Hazard Mitigation, Geological Agency (CVGHM), (Pusat Vulkanologi & Mitigasi Bencana Geologi, Badan Geologi-PVMBG), reported that a pattern of increasing seismicity from Merapi had begun to emerge in early September. Observers at Babadan west and Kaliurang south of the mountain reported hearing an avalanche on 12 September 2010. On 14 September 2010 white plumes were observed rising above the crater. Lava dome inflation, detected since March, increased from background levels of per day to a rate of per day on 16 September. On 19 September 2010 earthquakes continued to be numerous, and the next day CVGHM raised the Alert Level to 2 (on a scale of 1–4).
2010 eruptions of Mount Merapi | Recent background
Moreover, the Lassen volcanic center poses threats to visitors from sudden avalanches that could be entirely unrelated to eruptive activity. Due to the threat of an avalanche from nearby Chaos Crag if volcanic activity renewed in the area or an earthquake occurred, the Visitor Center for Lassen Peak located at Manzanita Lake closed in 1974. In 1993, a rockfall with a volume of fell down Lassen Peak's northeastern flank, but no visitors were harmed. Despite the volcano's current quiet state, rockfalls still pose significant hazards due to the peak's inherent instability.
Lassen Peak | Recent activity and current threats
The volcano resumed natrocarbonatite lava flow which started to fill the large crater from the 2007-2008 eruption. As of July 2013, there is a large active hornito on the western edge of the crater floor. During June, residents near the volcano reported several earthquakes. The new crater is inaccessible and climbers have only occasionally glimpsed into it.
Ol Doinyo Lengai | 2013
The largest single boulder found in the slide, near the site of Ranrahirca, weighed . The slide dammed the Río Santa, causing it to back up in a long lake. Material traveled as much as vertically up the opposite bank, destroying part of Matacoto village, before reversing and falling back into the river with a thunderous roar. Survivors described the motion as "like a wave on the shore." Within thirty minutes the landslide dam overflowed, and debris and mud flowed downstream for some at speeds up to per hour, causing damage all along the river banks. In Caraz, downstream of Yungay, the airport and much of the surrounding farmland were flooded, and a highway bridge at Choquechaca was destroyed.
1970 Huascarán debris avalanche | Effects elsewhere
For the 2010–30 period an eruption of Volcanic Explosivity Index 2 or more is expected based on statistics. As of 2020 such eruption has not happened. Research that models the internal architecture of the volcano indicate that Llaima has reached its maximum height and that any large eruption of lava will likely occur from flank vents and not from the summit.
Llaima | Future eruptions
After mid-2008, the number of volcanic earthquakes close to Ngauruhoe declined to the background level. Regular measurements of volcanic gas levels and the temperature of a summit gas vent failed to record any significant changes over the subsequent two and a half years. GNS Science accordingly reduced the alert level for Ngauruhoe to Level 0 on 2 December 2008. “The reduction in earthquake activity means that an eruption in the near future is unlikely without further earthquakes or other changes and the appropriate alert level is therefore zero”, said GNS Science Volcano Section Manager Gill Jolly. An increase in seismic activity in March 2015 resulted in the alert level being raised to Level 1.
Mount Ngauruhoe | Recent activity
More than 9,000 people live in the danger zone. Ash fall from an eruption could extend southeastward to the border with Chile]and affect the towns of Candarave, Ilabaya, Pachia, Palca and Tarata. Volcanic earthquakes like the 1999 Ticsani earthquakes at a volcano farther north and volcanic gases constitute additional dangers.
Yucamane | Hazards
At some point between the Pleistocene and the Holocene, the western flank of the volcano collapsed, generating a giant landslide that spread west and formed a large, hummocky landslide deposit. The avalanche crossed and dammed a previously existing drainage, impounding or enlarging Lake Chungará; numerous other lakes now forming the headwaters of the Rio Lauca sprang up within the deposit. Volcanic activity rebuilt the cone after the collapse, cancelling out the collapse scar. Parinacota had numerous effusive and explosive eruptions during the Holocene, the latest about 200 years ago. While there are no recorded eruptions, legends of the local Aymara people imply that they may have witnessed one eruption.
Parinacota (volcano) | Introduction
With a warming climate, increased rain and increasing glacial meltwater may accelerate edifice collapse. This has potential implications for more landslide hazards in the area of the volcano, and tsunami risks in the lake area.
Yate (volcano) | Future Dangers
Following an earthquake in 2004, several cubic meters of rock split from the cliff face behind the second cascade. The safety hazard thus created led park authorities to limit access to the cascade to no closer than a bridge just downstream. Heavy rains in 2005 and 2009 only exacerbated the problem by leaving the terrain more unstable.
Carbet Falls | Recent events
Hualālai (pronounced in Hawaiian) is an active volcano on the island of Hawaii in the Hawaiian Islands. It is the westernmost, third-youngest and the third-most active of the five volcanoes that form the island of Hawaii, following Kīlauea and the much larger Mauna Loa. Its peak stands above sea level. Hualālai is estimated to have risen above sea level about 300,000 years ago. Despite maintaining a very low level of activity since its last eruption in 1801, and being unusually inactive for the last 2,000 years, Hualālai is still considered active, and is expected to erupt again some time within the next century.
Hualālai | Introduction
The leak of this report, which is presumed to have been made by the Lava Jato Commission chaired by Rosa Bartra, would have been with the intention of further identifying the credibility of the President of the Republic. But the death blow for PPK came a few days later.
2017–2020 Peruvian political crisis | Second request for a presidential vacancy by the Congress of the Republic
An increase in seismic activity during February to April 2002 was followed by raising alert on the volcano. An ash eruption occurred on November 28, 2002.
Kanlaon | 2002
A landslide at Broken Top, or an eruption from the nearby South Sister, could initiate a lahar (rapid flows of water, rock, and mud) that could cascade down river valleys in the surrounding area. While smaller landslides of less than are more probable than huge avalanches, they can still cause significant damage and cause lahars. Larger landslide events would most likely be the result of magma intrusion, and thus they would be predicted in advance by seismometers and volcanic surveying devices. An eruption from South Sister would pose a threat to nearby life, as the proximal danger zone extends from the volcano's summits.
Broken Top | Recent history and potential hazards
The National Disaster Management Agency provided face masks and food to assist the evacuees. On Friday 3 September 2010, two more eruptions were noted. The first one happened at 4:45 a.m., local time, forcing more villagers to leave their houses – some of them had just returned the day before. This eruption was the most intense so far, with ash spewed up into the atmosphere about high. Some hours before the eruption a warning had been issued through the volcanology agency, and most villagers were prepared to leave quickly. A second eruption occurred the same evening, around 6 p.m. The eruption came with earthquakes which could be noticed out to a distance around the volcano.
Mount Sinabung | 2010
There were also concerns that rains from Typhoon Noul could trigger lahars and mudslides near the mountain. However, after Noul recurved to the north, the threat did not materialize and the evacuees were permitted to return to their homes. On June 16, Mount Bulusan generated two volcanic eruptions with the first one recorded at 11:02am which lasted for 10 minutes producing a one kilometer high grayish steam and ash plume and accompanied by rumbling sounds. The second one was recorded at 11:20am which lasted for a minute producing only a small ash plume. On June 18, the volcano once again erupted but was not observed visually due to thick clouds covering the summit.
Mount Bulusan | May–June 2015
The USGS is currently in the process of upgrading its aging monitoring and telemetry equipment, using American Recovery and Reinvestment Act funds. The agency plans to add another seismometer and three more sensors to help monitor activity. In addition, the HVO uses GPS to measure slight changes in tilt and slope of Hualālai, indicative of magmatic movement. A survey has been conducted every two years since 1986, but no changes have been recorded.
Hualālai | Future monitoring
A second phase of eruptive activity has not yet occurred, and it does not necessarily follow that it will occur.
2011–12 El Hierro eruption | Introduction
The volcano complex comprises remnants of multiple eruptive centres, which periodically have collapsed to form huge debris avalanches. The largest of these avalanches extended more than 50 kilometres from its source and covered more than 300 square kilometres.
Acatenango | Description
The government evacuated tens of thousands of people; 48 hours later, the volcano erupted as predicted. It was Popocatépetl's largest eruption for a thousand years, yet no one was hurt.
Prediction of volcanic activity | Seismic case studies
Word about these phenomena spread, and local tourism increased significantly.
Pacaya | Recent eruptions
In recent years there have been frequent temporary evacuations of nearby villagers due to threatening volcanic activity. Eruptions have occurred in 1991, 1998–1999 and from 2001 to the present day, with activity being characterized by extrusion of viscous lava forming a lava dome, and occasional larger explosions, forming pyroclastic flows and dusting the areas surrounding the volcano with ash and tephra. The largest eruption for several years occurred on May 24, 2005. An ash cloud rose to more than 3 km over the volcano and satellite monitoring indicated that the cloud spread over an area extending west of the volcano in the hours after the eruption.
Volcán de Colima | Current activity
Though the remaining ridge appears to be a steep and weathered fault scarp evidence suggests the geographic features are from wind and water rather than the landslide event. The volcano collapsed nearly in half at the caldera with the eastern half falling into the ocean cataclysmically with enough force to send debris including the massive Tuscaloosa seamount across the ocean floor and up a ridge. This landslide created a massive tsunami which ravaged the islands and possibly the Western coast of ancient North America.
Nuʻuanu Slide | Introduction
Williams' 1944 paper defined the basic outline of the Three Sisters vicinity, though he lacked access to chemical techniques and radiometric dating. Over the past 70 years, scientists have published several reconnaissance maps and petrographic studies of the Three Sisters, including a detailed geological map published in 2012. Neither North nor Middle Sister is likely to resume volcanic activity. An eruption from South Sister would pose a threat to nearby life, as the proximal danger zone extends from the volcano's summits. During an eruption, tephra could accumulate to in the city of Bend, and mudflows and pyroclastic flows could run down the sides of the mountain, threatening any life in their paths.
Three Sisters (Oregon) | Recent history and potential hazards
The northern wall of Mount Huascarán was destabilized, causing a rock, ice and snow avalanche and burying the towns of Yungay and Ranrahirca. The avalanche started as a sliding mass of glacial ice and rock about wide and 1.6 km (1 mile) long. It advanced about to the village of Yungay at an average speed of 280 to 335 km per hour. The fast-moving mass picked up glacial deposits and by the time it reached Yungay, it is estimated to have consisted of about 80 million m³ of water, mud, rocks and snow.
1970 Ancash earthquake | Landslide
Llullaillaco has been active in historical time, with the last eruption occurring in the late 19th century. Eruptions were recorded in February 1854, September 1868, and May 1877, involving two explosive eruptions and one with lava flows. According to a report in 1899, during the 1868 eruption large fissures opened on its slopes. The last eruption consisted of smoking reported at the time of the 1877 Iquique earthquake. The volcano is currently considered dormant and there are no known fumaroles. Future eruptive activity may cause sector collapses, although they would be a small danger to human life, given that the area is sparsely inhabited.
Llullaillaco | Eruptive history
Solfataric activity is ongoing. In 1985 and 1987 yellow (sulfur-bearing) steam clouds were reported, reaching heights of above the summit. The fumaroles cluster in two places, in the crater and on the southern flank where they reach over down. The fumaroles are reported to make "jet"-like noises and temperatures range from , ASTER imaging has indicated temperature anomalies of up to 8 kelvins. Water vapour and carbon dioxide making up the bulk of the gases, other components are hydrogen chloride, hydrogen fluoride, hydrogen sulfide, methane and sulfur dioxide. Mud pots have also been observed. Likewise, the volcano features ongoing seismic activity, including about two earthquakes per day and three seismic swarms in 2011–2012.
Guallatiri | Eruptive activity
Additionally, part of the northern flank of the amphitheatre collapsed during the eruption, with some of the debris falling into the Río Tambo canyon.
Huaynaputina | Caldera collapse
These two phases lasted just over a year and account for more than 90% of the total material ejected from the cone, as well as almost four-fifths (330 meters) of the final height of 424 meters from the valley floor. It also sent ash as far as Mexico City. The third ("Taqué-Ahuan") lasted from January 8, 1944 to January 12, 1945 and featured mainly the formation of a series of cracks on the south side of the cone, as well as an increase in activity in the center. Lava flows from this time mostly extend to the west and northwest.
Parícutin | Phases
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 recent history (1768, 1877) by lahars caused by volcanic activity.
Cotopaxi | Recent activity
Two fatal incidents have happened in modern history due to volcanic gas emitted from the northern group. On 12 July 1997, three soldiers of the Japan Self-Defense Forces died after gas accumulated in the valley they were training in. On 20 June 2010, a teenage girl died after being exposed to volcanic gas near Sukayu Onsen. After the 2011 Great East Japan earthquake, seismic activity around the volcanic group increased. After a series of earthquakes between February and October 2013, Mount Ōdake saw a degree of deformation. Future eruptions are forecast to come from the peak of Mount Ōdake and Jigokunuma, a volcanic crater lake.
Hakkōda Mountains | Modern activity and the current threat
Humanity has never witnessed enormous collapses on La Palma and there is evidence that the western flank of La Palma is currently stable and a collapse in the near future unlikely. A worst-case scenario giant landslide like the one modelled by Ward and Day 2001 is a very low probability event, probably much less common than once per 100,000 years which is the probable occurrence rate of large landslides in the Canary Islands. A smaller landslide scenario, which Tehranirad "et al." 2015 defined as "extreme credible worst case scenario", has a recurrence rate of about once every 100,000 years. Because of their low incidence probability, the hazard from large flank collapses at La Palma is considered to be low.
Cumbre Vieja tsunami hazard | Probability
The relatively low population density on the Bolivian side of the volcano means that renewed activity would not constitute a major threat there, although the town of Sajama may be affected. The Arica-La Paz highway runs close to the volcano and might be threatened by mud and debris flows, along with small communities in the area. Communities close to the volcano include Caquena, Chucullo and Parinacota. Potential hazards from future activity include the development of lahars from interactions between magma and the ice cap, as well as eruptions from the flank vents; ash fall from prolonged flank vent eruptions could disturb pastures in the region.
Parinacota (volcano) | Present-day activity and hazards
Many farmers live in the paths of such possible destructive events. Although volcanic eruptions are notoriously chaotic in their frequency, some scientists warn that a large eruption is "overdue". Research from Massey University indicates that significant seismic activity is likely again in the next 50 years. Prevailing winds would probably blow ash east, covering much of the North Island, and disrupting air routes, power transmission lines and local water supplies.
Mount Taranaki | Hazards
A potentially greater hazard at Mauna Loa is a sudden, massive collapse of the volcano's flanks, like the one that struck the volcano's west flank between 100,000 and 200,000 years ago and formed the present-day Kealakekua Bay. Deep fault lines are a common feature on Hawaiian volcanoes, allowing large portions of their flanks to gradually slide downwards and forming structures like the Hilina Slump and the ancient Ninole Hills; large earthquakes could trigger rapid flank collapses along these lines, creating massive landslides and possibly triggering equally large tsunamis. Undersea surveys have revealed numerous landslides along the Hawaiian chain and evidence of two such giant tsunami events: 200,000 years ago, Molokaʻi experienced a tsunami, and 100,000 years ago a megatsunami high struck Lānaʻi.
Mauna Loa | Hazards
Also, the West Coast of America and the entire Pacific Rim could potentially be affected. Other research suggests that such a single large landslide is not likely. Instead, it would collapse as a series of smaller landslides. In 2018, shortly after the beginning of the 2018 lower Puna eruption, a National Geographic article responded to such claims with "Will a monstrous landslide off the side of Kilauea trigger a monster tsunami bound for California? Short answer: No."
Megatsunami | Hawaii
In September 1962, the Massachusetts Institute of Technology sponsored a glaciological expedition to assess the aftermath of the Ranrahirca slide. American climbers David Bernays and Charles Sawyer observed, in the aftermath of this slide, "a massive vertical slab of rock being undermined by Glacier 511" posing the threat of a much larger collapse. The overhanging cliff was as much as high in places and the rock was described as being "pervasively fractured." Although the risk to Yungay was remote, the town could be threatened if a "sufficiently large avalanche" were to spill over the ridge to its east. The Americans' findings were reported on September 27, 1962 in the "El Expreso" newspaper, under the headline "Dantesque Avalanche Threatens Yungay." Local authorities ordered this information to be retracted, and discouraged citizens from speaking about the threat, in order to prevent panic: "Anyone who spoke in favor of the Americans' conclusions would be charged under the Penal Code for disrupting public tranquility." The director of the regional Lakes Commission, Miguel Eliás Pizarro, was asked to "provide an expert analysis." Pizarro "dismissed the American mountaineers' statements as outlandish, hurried and uninformed" and stated that Yungay was in no danger, being well out of the path of the 1962 slide.
1970 Huascarán debris avalanche | Post-1962 observations and controversy
The second phase was estimated to be a VEI 4 eruption, which was large, but not nearly the most powerful eruption possible by volcanic standards. By way of comparison, the Mount St. Helens eruption of 1980 was rated as 5 on the VEI, and the 1991 eruption of Mount Pinatubo was rated as a 6. This second phase erupted trachyandesite.
2010 eruptions of Eyjafjallajökull | Background
This slide was not caused by an earthquake, nor were seven other large avalanches and debris flows that occurred in the Santa Valley between 1940–1970. Rather, the glacier had fractured under its own weight. Due to the steep slope of the underlying rock and lubrication by glacial melt, there was nothing to stop the ice from sliding downhill at high speed. In the wake of this and other glacier-related disasters in the Ancash region, notably glacial lake outburst floods that destroyed parts of Huaraz in the preceding two decades, the national government had tried to push forward "hazard zoning" which would limit development in flood and avalanche zones.
1970 Huascarán debris avalanche | 1962 Ranrahirca avalanche
This time a landslide took place, too, as a part of the crater wall falling apart on the northwest side. This phenomenon occurs sporadically, although this time the consequences were greater than usual. As a normal precaution, authorities declared a red alert, closed the road between La Fortuna and Tilarán, which runs around the north side of the volcano, and evacuated approximately 450 people (mostly tourists) from the immediate area, including several hotels and tourism-oriented businesses. There were no reports of injuries caused by the volcanic activity.
Arenal Volcano | May 5, 1998
In April 2005, the Directorate of Volcanology and Geological Hazard Mitigation raised an alert, forbidding visitors from going up the volcano. "Sensors on the slopes of the two mountains - Anak Krakatoa on the southern tip of Sumatra Island and Tangkuban Perahu in Java - picked up an increase in volcanic activity and a build-up of gases, said government volcanologist Syamsul Rizal." On the mountain's northern flank is Death Valley, which derives its name from a frequent accumulation of poisonous gases.
Tangkuban Perahu | Introduction
The ground began to bulge in late 1997, as magma started to pool about underground. Scientists became concerned that the volcano was awakening, but examination of interferograms, or diagrams of patterns formed by wave interference, revealed that only small amounts of deformation occurred. A 2002 study inferred that the composition of intruding magma was basaltic or rhyolitic. A map at the Lava Lands Visitor Center of the Newberry National Volcanic Monument south of Bend shows the extent of the uplift, which reaches a maximum of . In 2004, an earthquake swarm occurred with an epicenter in the area of uplift; the hundreds of small earthquakes subsided after several days.
Three Sisters (Oregon) | Recent history and potential hazards
The last eruption of the volcano was on January 1, 2008. The park had to be evacuated, including about 150 tourists and employees of CONAF, because at 18:20 hours local time the volcano Llaima erupted. During the eruption, launched vent s and solid material to a thousand feet above the main crater, located to 3,150 meters, authorities said.
Conguillío National Park | 2008 eruption
The volcano is considered to be potentially active because of the fumarolic activity, and SERNAGEOMIN publishes a volcano hazard index for Ollagüe. A seismometer array was deployed in 2010-2011. Future eruptions of Ollagüe may threaten the town of Ollague away and the highway .
Ollagüe | Recent activity and hazards
During September and October 2019, INGEOMINAS (Colombian Institute of Mining and Geology) noted gradual increases in seismic activity near the Arenas crater. Sulfurous odors and phreatic eruptions reported at Nevado del Ruiz prompted an alert level of Yellow on October 1. Chemical analysis of the volcano demonstrated deformative changes and geochemical alterations. Over the next four months a smattering of long-period earthquakes, considered pseudo-Tornillo events, raised worries that the volcano might erupt. In 2010, tilt increased, and on average 890 volcanic tremors were recorded monthly, roughly eight times as many as had been recorded from 2009–2010. 2010 marked the beginning of increases in sulfur dioxide emissions accompanying small eruptions at the volcano, which both peaked in February 2012 correspondent to a dramatic increase in earthquakes.
Nevado del Ruiz | Recent activity
In the third stage, Vulcanian eruptions took place at Huaynaputina and deposited another ash layer, which is thinner than that produced by the first stage eruption and appears to be partly of phreatomagmatic origin. During this stage the volcano also emitted lava bombs; the total volume of erupted tephra is about . This third stage destroyed the lava dome and formed the third vent, which then began to settle along the faults as the magma underneath the vent was exhausted. The fourth vent outside of the amphitheatre formed late during the eruption as well.
Huaynaputina | Third Vulcanian stage
Minor hydrothermal explosions could still potentially be dangerous, as the ejection of ballistic blocks or tall waves could threaten people standing near the lake, traveling at speeds from . Landslides could threaten visitors to the national park or researchers by creating tsunami-sized waves, also potentially damaging infrastructure surrounding the lake.
Mount Mazama | Recent activity and potential hazards
They do not appear to form through individual collapses; multi-stage failures lasting hours or days appear to be more common as has been inferred from the patterns of landslide-generated turbidite deposits in the Agadir Basin north of the Canary Islands. The most recent such event took place at El Hierro 15,000 years ago and was later re-dated to have occurred between 87,000±8,000 (margin of uncertainty) and 39,000±13,000 years ago. Many processes are involved in the onset of volcano instability and the eventual failure of the edifice. Mechanisms that destabilize volcanic edifices to the point of collapse include inflation and deflation of magma chambers during the entry of new magma, intrusion of cryptodomes and dykes, and instability of slopes under loading from lava flows and oversteepened lava domes.
Cumbre Vieja tsunami hazard | Sector collapses and tsunamis caused by them
The majority of the mudflow headed straight down Río Llanganuco, which formed the most direct path for the slide. The villages of Incayoc and Huashau, closest to the base of Huascarán, were struck first. A group of Czechslovak climbers on their way up the mountain were killed nearby. The entire Llanganuco delta area was destroyed, including the rebuilt town of Ranrahirca, where an estimated 1,800 people were killed. "An unknown, but probably large, number of additional casualties were sustained elsewhere in the extensive area covered by the debris lobe." As had occurred in Yungay, huge boulders were thrown hundreds of metres across the valley, destroying everything in their path.
1970 Huascarán debris avalanche | Effects elsewhere
Ngauruhoe erupted 45 times in the 20th century, most recently in 1977. Fumaroles exist inside the inner crater and on the rim of the eastern, outer crater. Climbers who suffer from asthma may be affected by the strong sulphurous gases emitted from the crater. A significant increase in earthquake activity in May 2006 prompted the alert level to be raised from zero (typical background activity, no signs of significant unrest) to one (signs of volcano unrest). Over the next two years GeoNet recorded an average of 5 to 30 earthquakes a day close to Ngauruhoe, though the maximum daily number was as high as 80.
Mount Ngauruhoe | Recent activity
The most recent eruption was in the period 1948 to 1953. During this period, Hibok-Hibok formed flank lava domes and produced pyroclastic flows that devastated coastal villages. The Camiguin Mindanao group is permanently monitored for volcanic and seismic activity.
Camiguin Mindanao | Volcanic Activity
On August 18, the PHIVOLCS reported a 20-meter steam emission from the volcano's main crater and several volcanic earthquakes within its vicinity. Subsequent earthquakes have been recorded until late August. The PHIVOLCS asserted that the volcanic activity was normal but advised local governments to remain prepared in case of an eruption.
2020 Taal Volcano eruption | Post eruption
In July 1993, there were reports of earthquakes and alleged drying up of vegetation at the upper slopes and summit area of the volcano but volcanologists said the earthquakes were of tectonic in origin and there was no significant change in the volcanic activity. In February 2004, there were reports of grayish steam clouds hovering above the summit but volcanologists from PHIVOLCS said the seismic swarm was of tectonic origin and the steaming activity was only wispy to weak.
Babuyan Claro Volcano | Recent reported activity
On March 19, 2008, there was a small explosion in Halemaʻumaʻu, the first explosive event since 1924 and the first eruption in the Kīlauea caldera since September 1982. Debris from the explosion was scattered over an area of . A small amount of ash was also reported at a nearby community. The explosion covered part of Crater Rim Drive and damaged Halemaʻumaʻu Overlook. The explosion did not release any lava, which suggests to scientists that it was driven by hydrothermal or gas sources. This explosion event followed the opening of a major sulfur dioxide gas vent, greatly increasing levels emitted from Halemaʻumaʻu.
Hawaiʻi Volcanoes National Park | Recent events
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 emissions. IGEPN reported slight deformation of the edifice, suggesting an intrusion of magma under the volcano. As of 25 July, the unrest continued, and the most recent significant eruption was a phreatic (ash and steam) eruption that occurred on August 14 and 15, 2015. Ash 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.
Cotopaxi | Recent activity
A new eruption period started on 2 September 2013 with a phreatic explosion, which was followed by more events in the next few days. Strong but variable seismic activity, the observation of thermal anomalies in satellite images and the exhalation of gases characterized this eruption period. Lava effusion began in the summit crater in 2014 and increased after the 2014 Iquique earthquake, culminating in an explosive eruption on April 19, 2014. Volcanic activity decreased afterwards until September 2014. The eruptions were accompanied by earthquakes, rumbling noises from the volcano, ash fall and the forceful ejection of large blocks. In light of the volcanic activity, Peru declared a state of emergency in August 2013 and evacuated the village of Querapi at Ubinas, whose population returned in 2016; The evacuation of the town of Ubinas was also considered.
Ubinas | 2013–2014 eruption and later episodes
On July 2, 2008, another eruption resulted in evacuation of 40 people from a 15 km exclusion zone.
Llaima | Eruptions
Route 97, disabling transportation in the area, in addition to likely ruining gas pipelines and power lines that extend electricity to California, both of which would be accompanied by serious economic consequences. Flank lava flows, which would likely be basaltic in origin, might form lava fountains that could scatter cinders and lava for several thousand meters, building cinder cones or initiating forest fires. While the flows themselves move at rates of per minute, and thus could be escaped by animals and humans, they would destroy stationary structures in their paths. Pyroclastic flows, on the other hand, travel at speeds of , and their violent force could incinerate or pulverize objects in their path, or asphyxiate living things.
Newberry Volcano | Recent activity and current threats
Presently, rock glaciers are active on the mountain. The volcano was constructed in two phases and postglacial lava flows have been found by Landsat imagery, but they are unsampled. A previously identified southeastern lava flow has been later identified as a debris avalanche. A dacitic lava dome is found southwest of the volcano and is named Calajata. In a 2011 hazard map Arintica was considered a potentially dangerous volcano of Chile. Whether the volcano was active in the Holocene is contentious. A belt of "Polylepis" woods surrounds the volcano.
Arintica | Introduction
On 5 August 2018, a second earthquake struck Lombok, causing more landslides and small tsunamis due to its proximity to the northern coast. The area around Rinjani was evacuated due to concerns of a possible eruption, but no increase in activity was detected at Rinjani or the nearby volcano Mount Agung on Bali.
Mount Rinjani | August 2018
The relative unpreparedness of the residents in the area caused by the lull in activity would worsen the consequences of such an event. The area near the volcano has been inhabited for centuries by Hawaiian natives, dating back to before recorded history. The coast west of Hualālai in particular had several royal complexes. The volcano is also important ecologically, is home to many rare species and several nature reserves near the summit, and is a popular hiking attraction. Today the coast near Hualālai is dotted by vacation resorts, some built on historic flows, and a National Historical Park.
Hualālai | Introduction
Between 8-4 million years ago large scale eruptions occurred, such as these at Cerro Panizos, Coranzulí, Vilama, Cerro Guacha and La Pacana. Volcanic activity decreased by the Pleistocene, during which activity occurred within the La Pacana caldera and at Cerro Purico, with the most recent eruptions formed the Cerro Chao dome and the Cerro Chascon-Runtu Jarita complex. Ongoing surface deformation at Uturunku is viewed as a sign that volcanic activity in the Altiplano-Puna volcanic complex is still ongoing. Seismic imaging shows the existence of a partially molten magma body in the crust beneath the Altiplano-Puna volcanic complex.
Vilama (caldera) | Geology
More recent volcanic activity was phreatic and phreatomagmatic and formed the summit craters. The occurrence of recent volcanic activity and its location on the Olca-Paruma complex is unclear. An unconfirmed flank eruption occurred in 1865–1867 on Olca; it may have occurred on Volcan Paruma, however. Fumarolic activity has been ongoing for over sixty years, and may have spiked in November 1989 – March 1990 when seismic and fumarolic activity occurred at the volcano. During that instance, strong fumarolic activity was observed on 13November 1989 from Ujina, and seismic activity was reported in mid-March of the subsequent year. This fumarolic activity occurred in coincidence with earthquakes at Iquique on the coast.
Olca-Paruma | Eruption history
The Bolivian Police assured that there is no risk of a new attack and that there is a device deployed in the city. It has been criticized that the government did not exercise any preventive measure and that the second explosion would have been avoided had it not been for their ineptitude. Three suspects who were in the explosion site were arrested the following day, of which two of them circulated in a vehicle that presented damage presumably produced by explosives. Later, it was discovered that they were not related to the attack and that they were separated at the time of the explosion, but they continued to be detained because of the possession of illegal weapons.
2018 Oruro attacks | Second explosion
The 1970 Huascarán debris avalanche occurred on May 31, 1970 when a debris avalanche and mudflow triggered by the Ancash earthquake destroyed the Peruvian town of Yungay and ten nearby villages, leaving up to 18,000 people dead. It is the most deadly avalanche or glacier-related disaster in history, and the third or fourth most deadly landslide-related disaster of the 20th century, after the Haiyuan landslides (China), the Armero tragedy (Colombia) and by some estimates the Khait landslide (Tajikistan). The north peak of Huascarán from which the avalanche originated had been considered unstable since 1962, when a smaller collapse wiped out several villages of the Callejón de Huaylas valley near Yungay.
1970 Huascarán debris avalanche | Introduction
The other important criterion is the lava flow coverage rate. Using the preliminary dates for Haleakala flows, only of lava flows have been emplaced in the last 900 years. In comparison, approximately of Hualalai are covered with flows 900 years old or younger and approximately on Kilauea and on Mauna Loa are covered by lavas less than 200 years old. Thus, Haleakala is a distant fourth in coverage rates.
Haleakalā | Volcanic hazard
Volcanic activity at Taapaca occurred in several stages starting during the Plio-Pleistocene. The emplacement of lava domes was often followed by their collapse and the formation of block-and-ash avalanches, and parts of the volcano underwent sector collapses (large landslides). It was at first assumed that activity ended during the Pleistocene, but late eruptions occurred until 2,300 years ago; the latest is dated to 320 BCE. The Chilean Geological Service monitors the volcano as it is a hazard to Putre, but eruptions could also impact local roads and areas as far east as Bolivia.
Taapaca | Introduction