A Discussion Of The Eruption Mt Helena

A Discussion Of The Eruption Mt. Helena In 1980 Essay, Research Paper

Over the past 15 old ages significant developments have been made within high magnitude-low frequence vulcanology. It is now going progressively possible to foretell an eruption ; to understand the procedures of eruptions and to develop relevant responses and accommodation programmes ( Chester 1993, McCall 1992, White 1972 ) . Yet, irrespective of this there are jobs. Although scientific discipline has developed new anticipation methods, the truth of these is difficult to judge, as despite frequent high magnitude-low frequence eruptions during the Holocene, they are now comparatively rare, therefore doing adjustment programmes debatable. Volcanologists have nevertheless, decided upon two types of programmes ( McCall 1992 ) . First, foretelling the vent & # 8217 ; s hereafter eruptions, carried out through analyzing past behavior and secondly, puting up lasting monitoring systems leting for rapid sensing of new seismal activity. General planetary programmes can non be augmented nevertheless, but, in the wake of an eruption the responses and accommodation made can be assessed and can be used as guidelines for future high magnitude-low frequence volcanic countries. The Mount Saint Helens & # 8217 ; eruption was one of high magnitude-low frequence and accordingly other states have turned to the responses and accommodations made by Washington State to develop their ain programmes. This essay will analyze the responses and accommodations made by Washington State and their consequence on programmes developed by Japan, New Zealand, the Philippines and the Indonesian authorities in relation to Una Una. Studies into Mount Saint Helens, situated in the volcanic part of the Cascade Mountains in Washington State, USA, began chiefly in the late 1930 & # 8217 ; s by Verhoogan ( Geological Survey Prof. Paper 1982 ) . His initial study based on a survey of stones and flora, concluded that there had been volcanic activity until late due to surveies uncovering the lava to be merely a few 100 old ages old ; but it was non until the 1970 & # 8217 ; s involvement into Mount Saint Helens increased due to the realization of its possible perilousness, motivating The Congress Under the Disaster Relief Aid ( 1974 ) to present a brief to the United States Geological Survey ( USGS ) saying their beliefs of a possible eruption and proposing possible responses and accommodations that could be implemented in the event of the catastrophe ( Chester 1993 ) . In drumhead, they believed the premier purpose was to cut down loss of life, belongings and natural resources that frequently takes topographic point as a consequence of vent & # 8217 ; s eruptions and its related effects, such as land-slides and clay flows. As a consequence of the initial brief, stairss were taken based on the suggestions made, to guarantee the selected purposes would be met. First, the USGS published a jeopardy map of the country and secondly, they informed the relevant bureaus of the warning marks of an eruption and the subsequent guidelines that need to be taken, for illustration, curtailing entree to certain countries. As will be seen subsequently these initial stairss proved successful. In 1975 Dwight Crandell and Donal Mullineaux wrote an article warning of an at hand eruption of Mount Saint Helens within the following 100 old ages and possibly even before the terminal of this century ( Geological Survey Prof. Paper 1982 ) . They wrote of the eruptive history of the vent and produced districting maps, foretelling those countries which would be most effected. Later, Crandell and Mullineaux wrote a farther, in depth study ( 1978 ) commissioned by the USGS, titled, & # 8220 ; Potential Hazards from Future Volcanic eruptions of Mount Saint Helens Volcano, Washington & # 8221 ; ( Chester 1993 ) . Its publication came approximately as a consequence of a new research programme look intoing the possible jeopardies in the Cascade Region. From their old appraisals of the country and their subsequent studies they demonstrated that future eruptions will be of high magnitude, bring forthing lava flows, pyroclastic flows, domes, tephra and clay flows & # 8211 ; therefore going risky for a battalion of people within the country. This study was widely distributed to the Washington State Governors representatives, Federal and State functionaries and local bureaus in south-west Washington. The Governors representatives misinterpreted the papers and thought an eruption was at hand. As a reaction to the study, although at the clip being thought of as an overreaction, monitoring and appraisal of the vent commenced ( Saarinen and Sell 1985 ) . From the get downing the monitoring procedure proved debatable as cognition of past eruptions was comparatively thin, both for Mount Saint Helens or similar Cascade part eruptions every bit good as for other high magnitude-low frequence eruptions worldwide. Monitoring of the vent included put ining seismometers to observe temblors meaning an at hand eruption through monitoring precise land surface motions and observing swelling in the vent. Despite this study being credited for the monitoring and assessment systems set up in the vent & # 8217 ; s locality, the study ( referred to as the & # 8220 ; Blue Book & # 8221 ; ) however caused jobs amongst many groups including the general populace, chiefly due to it beliing the current and recognized perceptual experiences of hazard & # 8211 ; therefore the study can be partially to fault for the misinterpretations that arose ( Chester 1993 ) . Two factors contributed to the confusions. First, the last Mount Saint Helens eruption was in 1857 and the last volcanic activity in the Cascade part was between 1914 and 1921, therefore the people were loath to believe another eruption was at hand. Second, those involved in the study had small experience in foretelling the class of vents, therefore frequently information released was inaccurate. Although clearly the study bought about confusions, however, in retrospect, it is possible to see how accurate their anticipations were & # 8211 ; one of their chief booby traps was that the failed to foretell the strength of the blast. By the beginning of March 1980, when the first marks of temblors became evident, the lone instrument supervising the vent was a seismometer situated on the western wing. From this instrument the early warning marks were registered and activity bit by bit increased ; farther instruments were installed and aerial observations were carried out ( Geological Survey Prof. Paper 1982 ) . Again after the little eruption on March 27th, 1980, the programmes and systems were intensified. At all times, functionaries within the State and the environing country were unbroken intelligent as were bureaus and the general populace. The United States Forest Service ( USFS ) lead the intelligence conferences which were broadcast three times a twenty-four hours on both the wireless and the telecasting. From analyzing the monitoring and warning procedure & # 8217 ; carried out before the eruption and from seeing the responses and accommodations made after the eruption, the effectivity of these initial actions can be measured and from it changes can be implemented for the hereafter. In retrospect, the responses and accommodations taken proved to be both successful and unsuccessful ( Chester 1993 ) . Successful facets include the velocity at which the USGS set up monitoring Stationss and produced and distributed jeopardy maps after the initial temblors in March. Through this rapid procedure it enabled scientists and volcanologists to verify their sentiment of an at hand eruption to functionaries and the general populace. Interaction between the USFS and the USGS was good, chiefly because the vent lay within their land. They created zones within the country and by March 27th, they had set up & # 8216 ; no public entree zones & # 8217 ; and & # 8216 ; restricted entree zones & # 8217 ; . Roadss were shut and the dwellers were to the full informed guaranting the emptying programs were widely known. Another positive facet of the responses and accommodations were those taken by the Federal Emergency Management Agency ( FEMA ) ; they became involved after the chief eruption of May 18th, one time President Carter had declared it a catastrophe country. They successfully coordinated the hunt and deliverance programme and the disposal of catastrophe alleviation ; in add-on, they developed technological information webs guaranting relevant information could be widely spread. Despite the positive facets of the responses and accommodations, there are nevertheless, negative 1s. Research carried out after the eruption to measure success or failures shows that the warnings were non to the full effectual due to their incompatibility ; frequently they were ill-defined or did non to the full stress the possible dangers, for illustration, despite Crandell and Mullineaux & # 8217 ; s warning of pyroclastic flows to the E of the vent in their & # 8220 ; Blue Book & # 8221 ; , they were non given the significance they should hold had, therefore those countries did non develop eventuality programs. It is now thought that if the USGS had played an increased function and developed better communications this job could hold been alleviated. A farther negative facet is that despite the USFS proving to be efficient, its eventuality programs were based on the consequences of their experience of wood fires. Although this was an equal starting block, the programs should hold been advanced as the graduated table of the volcanic jeopardy was far greater than any old jeopardy posed by a wood fire. Additionally the State of Washington must allocate some of the incrimination. For despite being a risky country due to the vents, their exigency services were severely coordinated and underfunded. Finally FEMA merely became involved one time President Carter, declared the province a catastrophe country & # 8211 ; loss, chiefly of stuff goods could hold been reduced had they become involved earlier. With about complete certainty, Mount Saint Helens will break out once more, although it is about impossible to foretell when ( Geological Survey Prof. Paper 1982 ) . Seismologists at the University of Washington and the USGS are comparatively optimistic that the form of pre-eruptive activity will be important in supplying a warning of an eruption. Through more recent surveies into the success of the responses and accommodations made in 1980, extra 1s can be developed and unsuccessful 1s altered. After the following eruption hence, the subsequent loss of life, belongings and natural resources will be kept to a lower limit. In add-on to the advanced response programmes that will be implemented when a future eruption commences, other stairss have been taken to rise people & # 8217 ; s consciousness of the possible perilousness of Mount Saint Helens, for illustration, information Centres have been set up within the country enabling people to understand the consequence a volcanic eruption can hold. Crandell and Mullineaux & # 8217 ; s work and studies into Mount Saint Helens accurately predicted the eruption and the accent they placed on the dangers of such high magnitude-low frequence eruptions was successful. Had they non placed such accent on the possible dangers, it is certain that the loss would hold been far greater. With sorrow, the lone ruin of their work was their inaccuracy in foretelling the strength of the blast. The Mount Saint Helens eruption was one of high magnitude-low frequence and in a developed state. Prior to it there had been few similar eruptions, therefore people were incognizant of its perilousness. As a consequence of the eruption, both developed, for illustration, Japan and developing states, for illustration, the Philippines have realised the hereafter dangers they could confront from their vents ; therefore the Mount Saint Helens catastrophe has prompted others to develop monitoring, surveillance and eventuality programs, so that in the event of a catastrophe, they will be every bit prepared as possible. Many states have based their programs on the successful facets carried out by Washington State and used their unsuccessful 1s to guarantee the same booby traps are non repeated. A small over 3 old ages ago, Japan experienced a high magnitude-low frequence volcanic eruption. Through their increased consciousness due to the Mount Saint Helens eruption, Japan found itself aptly prepared and through successful coordination, losingss were kept to a lower limit. In June 1991, Mount Unzen in Japan erupted after a drawn-out initial build-up. Yet despite many eruptions, pyroclastic and mud flows, comparatively few people were killed ( Chester 1992 ) . The few deceases ensuing from the eruption were impressive, given the fact that Japan has a really high population denseness. This success rate can be attributed to the first-class pre-planning and the effectual coordination and execution of the programs once the eruption began. Through the authorities & # 8217 ; s acknowledgment of the high denseness of population particularly around the vent, they and the general public became cognizant of the demand for pre-planning. Through larning from past errors made due to Washington State & # 8217 ; s under-funded and ill-equipped exigency services, they realised the importance of supplying significant resources, both technological and fiscal, for all facets ; including exigency services, surveillance experts and forces. The Japanese have developed a really hi-tech surveillance system, which is used to invariably supervise the most potentially unsafe vents ( Chester 1992 ) . As with Mount Saint Helens, the Nipponese authorities has drawn up hazard maps of the country, enabling bureaus, authorities functionaries and the local population to understand those countries which are most unsafe. In add-on, the authorities has besides set up the & # 8220 ; Nipponese National Programme of Predicting Volcanic Eruptions & # 8221 ; & # 8211 ; this was initiated by the eruption of Sukura-Zima in 1974 and Mount Saint Helens. Through developing those anticipation methods used at Mount Saint Helens, the Japanese were successful in finding the eruption. In add-on to this, the National Programme stressed the importance of a extended warning web and trained exigency services. As has been antecedently mentioned, portion of the mistakes of the Mount Saint Helens catastrophe ballad within the ill funded exigency and deliverance services. The Nipponese authorities found themselves in a place to larn from the errors of the USA authorities. Similarly to the Mount Saint Helens catastrophe, Japan & # 8217 ; s programs include emptying, this facet must be carefully worked out and revised due to the ever-changing population and economic system. The eruption at Mount Unzen was a terrible trial for the readiness of the state as a whole and for those within the locality. Equally shortly as initial activity began, in similitude to the Mount Saint Helens catastrophe, surveillance and monitoring was stepped up and anticipation methods used. Once volcanic stuff began to be ejected, the programs began to be bought into action ; people were evacuated and were merely allowed back one time the country was considered safe. The planned emptying proved successful due to its thorough development prior to the eruptions ; this is in comparing to Mount Saint Helens, where at times inconsistency within programs led to confusion, therefore Japan had learnt from Washington State & # 8217 ; s errors. ( See table 1 for responses and accommodations made in relation to volcanic activity ) Through this illustration, it can be seen that Japan coped good with the high magnitude-low frequence catastrophe ; the grounds behind this can be attributed to the first-class coordination and mobilization of resources. Japan will go on to be successful with such catastrophes due to its realization of the importance of pre-planning, proficient and fiscal support. Part of the success can be attributed to Japan & # 8217 ; s increasing consciousness of its possible jeopardies, which came about as a consequence of Mount Saint Helens. It was through analyzing Washington State & # 8217 ; s posi

tive and negative aspects that Japan managed to successfully develop their own strategies – thus despite the magnitude of the eruption they were able to keep their losses to a minimum. Such high magnitude-low frequency events also occur in New Zealand, although not with the same intensity as in Japan. Prior to the 1980 Mount Saint Helens eruption, volcanoes were not seen as being potentially hazardous. As a result of this disaster, New Zealand to, became interested in their volcanoes, with the realisation of the consequences of such an eruption (Dibble 1985). With increased technology and by learning from both the positive and negative responses made both before and after the Mount Saint Helens eruption, New Zealand found themselves to be in a better position for predicting and responding to volcanoes. In response, New Zealand set up a special Planning Committee on Volcanic Hazards, this committee has developed a number of actions to be taken to help minimise risk and devastation. These include (Dibble 1985) :- * The likely areas and types of future activity. * The risk to public safety. * The setting up of monitoring systems to predict the eruption. * Government resources that can be bought into use in the event. * Practical steps that can be undertaken by regional and local authorities where a threat is identified. New Zealand fully understood the need for pre-planning and recognised the extent to which the effects of the disaster could be reduced through specific programmes. In the light of this, initial investigations were augmented to assess the volcanic areas. Through scientific studies uncovering past eruptions, they calculated the probability of future ones; following on, they researched into the possible damages that could result from such an eruption; for example, the cost to the economy, people and livestock. From the results obtained and with the government’s dedication, successful programmes were coordinated. A good example of this is in Auckland. This volcanic district encompasses over 50 eruptive centres including the Auckland metropolitan area. To date the type of volcanic activity expected in this vicinity includes lava fountains of over 200 metres in height and subsequent lava flows, tuff deposits 10’s of metres thick and ejections of rock debris. From this the government have been able to comprehend the volcano’s severity and they expect few survivors close to the source. They also concluded that tidal waves could be possible. Additionally, through calculations they have been able to estimate the probability of eruptions, yet despite a low risk, the risk to resources, economy and people are high (Dibble 1985). AUCKLAND VOLCANIC FIELDS (for example, Panmure Basin) AREA DESTROYED 3-28 km PROBABILITY IN 100 YRS. 2.5 – 5 % POPULATION AT RISK 6000 – 100,000 PROPERTY AT RISK (M$) 64 – 3600 Clearly therefore, both Japan and New Zealand have benefitted from being able to gain insight into successful surveillance methods, responses and adjustments that should be implemented; but it is not purely these developed countries that have benefitted, but also less developed countries have been able to look to Mount Saint Helens to guide their decision and implementation process. On June 15th and 16th, after two months of initial activity, Mount Pinatubo in the Philippines erupted, an eruption lasting for 15 hours, spreading ash into the stratosphere and culminating in large pyroclastic flows. The area surrounding Pinatubo has a very high population as only 100 km southeast of the volcano is the capital, Manilla and only 15 km to the east, is one of the United States largest overseas military installations, with over 15,000 personnel. The responses and adjustments the authorities made were terrific, especially given the fact they are a less developed country – through looking in retrospect at the Mount Saint Helens eruptions, the Philippine government learnt from the American government and through this learning process they developed the ‘Philippine Institute of Volcanology and Seismology’ (PHILVOLCS) (Chester 1992). It was this institute that began the well-devised monitoring process two months prior to the main explosion. It was through studying plans made by Washington State, that the Philippine government and PHILVOLCS were able to understand the necessity of substantial pre-planning. Prior to the eruption they devised evacuation roots and prediction methods to be used; they also developed a series of ‘alert levels’ which were communicated to the public, warning of the predicted time for eruption (Guest 1991). (See table 2 showing the responses and adjustments made in relation to the volcanic activity.) Clearly then the programmes devised by the Philippines were successful and the country substantially gained from the Mount Saint Helens experience. This can evidently be seen by the fact that the responses and adjustments they made were not in keeping with other less developed countries and many successful aspects were similar to those made before, during and after the Mount Saint Helens eruption Another example of a less developed country setting up successful surveillance systems and contingency plans is on the Indonesian island of Una Una, where in 1983 the Cola Volcano erupted. Yet despite the nature of the country and economy as a whole, the country lived up to its reputation of being able to manage such a disaster excellently (Chester 1992). As a result of the Mount Saint Helens eruption, the government officials on the Indonesian island were able to assess the importance of certain factors and processes, thus they gave priority to scientific investigations, integrating these findings with civil defence measures and developing skilled responses and adjustments programmes. As seismic monitoring detected activity, as with Mount Saint Helens, the surveillance was rapidly stepped up and as minor explosions began, the evacuation procedure was implemented. As volcanic activity increased so did the speed at which they were evacuated and within 24 hours, the island’s residences had moved – an incredible feet made possible by the use of a large number of boats. The death toll, through excellent evacuation procedures, was zero, but due to the size of the eruption on a small island, virtually all housing, livestock and plantations were destroyed. Clearly the evacuation was a tremendous success, but recovery from the eruption will be a long, slow process, due to the poverty, lack of capital and insurance. The Mount Saint Helens eruption has been hailed as the most significant eruption this century. In its immediate aftermath and in years to come it can be used, firstly, as a symbol of the capabilities of a high magnitude-low frequency event and secondly, to help generate other response and adjustment programmes. Vast quantities of information was produced after the eruption which has proved and will continue to prove extremely useful. Clearly this eruption woke people in other high magnitude-low frequency volcanic areas into realising their potential. As has been seen, relatively soon after the event many other countries began monitoring and assessing their volcanoes and devising response programmes. In time, they too experienced similar eruptions, where-by, as a result of Mount Saint Helens, they found themselves well-prepared – even some of the less developed countries. Through their assessments and preparations they were able to keep losses to a minimum. Additionally, it is fully understood globally, that assessment techniques and response programmes must be continually revised and up-dated where necessary, especially in the light of improved science and technology. Furthermore, a number of measures should be taken to ensure success in all aspects, for example; * The importance of planning. * The role of the emergency services. * Hazard information and the public. The importance of planning Planning at all phases is essential for an effective response to a natural hazard as people cannot successfully respond to an unknown phenomena. Those responsible, for example, agencies and officials, must plan in advance aspects such as evacuation and search and rescue procedures. Once this has been carried out they must ensure the information is accurately relayed to the public. Following on from the responses and adjustments made after the Mount Saint Helens eruption, there is substantial evidence showing that the most successful aspects were those where plans had been taken from similar past experiences, for example, despite not fully knowing how to deal with the problem of fallen ash, the emergency services treated it in a similar way to a snow storm; this proved to be very successful. Through innovation potential problems can be overcome. The role of the emergency services A successful emergency service is paramount. Not only must the rescue operation be expertly coordinated, with good communication to all involved, but the services and agencies must intervene early on. This was one of the prime mistakes made by Washington State in the wake of the eruption. FEMA became involved relatively late, thus perhaps decreasing the success of their efforts. But through the recognition of this other countries have been able to learn from the mistakes. Furthermore, the emergency services must have adequate resources available to them, both technical and financial, ensuring nothing can hinder their role. Hazard information and the public When faced with a disaster such as a volcanic eruption, a good ‘public information organisation’ is essential. The organisation must gather news from emergency operations, provide press conferences and ensure professional people within the field are consulted. Subsequently, the information must be relayed widely, accurately, quickly and simplistically to the public, ensuring all who could be effected are informed. FEMA took control of this aspect and to date it is probably the finest example of how it should be done. They ensured information was conveyed quickly and accurately at the same time as consulting experts within the field. Clearly then, it is possible to reduce the effects of such an eruption through careful monitoring and planning. But due to a major restricting factor often being financial resources, this could prove to be problematic for less developed countries. In this case they must be innovative and resourceful and develop programmes to the best they can, as was seen by the Indonesian government on the island of Una Una and the Philippine government in relation to Mount Pinatubo. There are certain aspects which are going to be poorly devised, but through assessment after the eruption, other countries can continually revise their own programmes, thus there must be a world wide flow of information ensuring all areas with similar volcanoes can benefit. This flow of information can come through The International Decade for Disaster Reduction, which developed due to increasing reports by mainly the media on large natural disasters. The aims for the decade were stated by the United Nations General Assembly as reducing loss of life and property and minimising social and economic disruption, especially in less developed countries. It set out four main goals. (Burton et al 1993) Firstly, improving the ability of a country to mitigate a disaster and where necessary, supply warning systems. Secondly, to devise appropriate strategies, taking cultural and economic diversity into account. Thirdly, to use comtemporary scientific and engineering skills to reduce loss of life and property. Fourthly, to develop ways of assessing, predicting and mitigating natural disasters through training and educating those involved, demonstration programmes and transferring relevant technology. Through international support, less developed countries should therefore see a reduction in damages to their country and a reduction in the number of deaths. But for success, all who could be effected by a disaster will have to be shown how they can help themselves – the aims set out by the United Nations are high and towards the latter half of this century, their success can be measured. BIBLIOGRAPHY Burton et al (1993) The Environment as Hazard; Guilford, Guilford Press Chester, D (1993) Volcanoes and Society; Edward Arnold Dibble et al (1985) Volcanic Hazards of North Island, New Zealand-Overview; Journal of Geodynamics 3, p. 369-396 Geological Survey Professional Paper 1249 (1982) Volcanic Eruptions of 1980 at Mount Saint Helens-The First 100 Days; US Government Printing Office Guest, J (1991) Unzen Volcano 1 Guest, J (1991) Mt. Pinatubo McCall, G et al (1992) Geohazards; London, Chapman and Hall Raphael, B (1986) When Disaster Srikes; Hutchinson Education Saarinen and Sell (1985) Warning and Responses to the Mount Saint Helens Eruption; New York, State University Press Shimozuru (1983) Volcanic Surveillance and Predictions of Eruptions in Japan; in Tazieff and Sabroux, Forecasting Volcanic Events, Developments in Volcanology 1; Amsterdam, Elsevier p.173-193 White (1973) Natural Hazard Research; in Chorley, Directions in Geography; London, Methuen p.193-212 TABLE 1 – The responses and adjustments made in the Mount Unzen vicinity in relation to volcanic activity. 1989 November – First volcanic tremor felt 1991 January 15 – Earthquake swarm Early April – Ash emissions May 12 – Volcanic glass recognised May 15 & 19 – Debris flows along Mizanushi River destroying two bridges. Evacuation of 1300 from Shimabara May 21 – 1100 evacuated at 0300. Allowed to return at 0555. May 23 – Domes grows and explosion produce grey clouds, 100m high. May 24 – Large explosion at 0810 produces pyroclastic flows 1300 evacuated due to risk of mud flows Material dredged from dams at night to reduce mud flow danger. May 25 – 0600 evacuation recommendation was withdrawn Dust and ash seen at 1145 Lava dome grows May 26 – Pyroclastic flows continue to within 600 metres of Kata-Kamikoba Evacuation of 3500 May 27 – Evacuation zone expanded Pyroclastic flows continue June 3 – Pyroclastic flows kill 41 and enters Kata-Kamikoba Helicopter grounded due to ash in engine June 7 – Evacuated zone increased – total evacuees= 7200 June 8 – Large pyroclastic flows Evacuation zone increased – total evacuees= 8500 73 houses destroyed June 9 & 10 – Evacuation zone increased – total evacuees= 9800 Mud flow hazard high June 11 – Large explosive event Houses, cars, windows and two helicopters damaged June 24 – Pyroclastic flows continue June 17 – Evacuation zone increased – total evacuees= 10,000+ TABLE 2 – The responses and adjustments made in the Mount Pinatubo vicinity in relation to volcanic activity 1991 April 2 – Explosion at eastern part of Pinatubo 2000 evacuated within 10 km radius June 3 – Tremor lasting 30 minutes June 4 – Tremor at 1200 June 5 – PHILVOLCS issued Alert Level 3 warning June 6 & 7 – 1000-2000 per day June 7 – Explosion from main vent at 1640 PHILVOLCS issued Alert Level 4 warning at 1700 12,000 people evacuated from Tarlac June 10 – US Air Force order evacuation of Clark Air Base at 0500 – 14,500 evacuees June 12-15 – Strong explosions, tephra columns reach 20 km Pyroclastic flows 600 more evacuees from air base Residents within 20 km are evacuated June 14 – Small mud flows 79,000 evacuated in total- 4 killed, 4 missing, 24 injured June 15 – Further explosions and pyroclastic flows Evacuated radius expanded by PHILVOLCS to 30-40 km 1342 – most violent phase June 16 – People return home June 19 – Death toll = 300