Executive summary
The Mount Ontake eruption, Japan, occurred on 27th September, 2014. The volcano is located on Honshu, central Japan, 200 km west of Tokyo, as indicated by figure 1a. There was great social, economic, and environmental disruption during and after the eruption, manly due to the ash that was expelled from the volcano. The early warning signs of the imminent eruption were missed or ignored, but it is possible an event like this could happen again. Thus my recommendations are:
Improve the quality and quantity of monitoring methods.
Build a coordinated volcano science community.
Improve forecasting of potential size, duration, and hazards of eruptions.
Implement more comprehensive early warning systems.
Public education of the dangers of volcanic eruptions.
Fig. 1
A. Illustrating Mount Ontake is located on at the conversion of 3 continental plates.
B. Showing the topography and relief of the volcano, indicating steep sides.
(Kaneko, Maeno, Nakada, 2016)
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Details of the Disaster
The Ontake eruption was measured as between 3 and 4 (Prezi, 2016) on the Volcanic Explosively Index (VEI) (Appendix 1). An eruption of this size is measured as having a plume of between 3-15 km tall and ejecting between 0.1 and 1 cubic kilometres of ejected tephra (geology.com, 2017). The most plausible cause of the eruption was the opening of a large crack 2 km long, 4.5 km wide, and 3 km deep (Murase et al., 2016) at 1100 meters below the surface of the mountain, due to increased pressure built up by steam. This created a tilt in the mountain, an indication of the impending eruption, which was noticed 7 minutes before the eruption (Earth & Space Science News, 2017). The seismometer also showed spikes of activity on the 10th and 11th of September, which could have caused the rip in the rock or vice versa. Seismic activity continued at a lower rate until the eruption (Koizumi et al., 2016), but this information was not acted upon in the period prior to the
Table 1.
A comparison of Mount Ontake eruption, Japan and Mount Sinabung, Indonesia.
(Prezi, 2015).
disaster.
The overall economic impact is unknown but the eruption was the deadliest to occur in Japan for 90 years (Earth & Space Science News, 2017). But, in comparison to similar types of eruption such as that of Mount Sinabung, Indonesia, the economic effects were limited.
Actions taken in advance
Japan is a highly volatile and volcanic region, it has 110 active volcanoes, 47 of which are currently being monitored (Cyranoski, 2014). In relation to the Geowarn early warning model (Appendix 2), Japan was able to conform to the emphasis on precautionary measures, when moving from green to yellow zone, to help mitigate disaster. Before the eruption, the mountain was equipped with 12 seismometers (Appendix 3.1), 5 Global positioning systems (GPS), and 1 tiltmeter (Appendix 3.2) (Cyranoski, 2014). Despite all the retrospective measures taken to monitor Mt. Ontake prior to the eruption, there were limited warning signs produced and the only early indications that were picked up were ignored. The seismic tremors, specifically noted in the orange zone of the model, were not prioritised by Japanese researchers, and due to the rapid progression of the eruption into the red zone, Japan were not able to take the required precautionary measures, such as the evacuation of the mountain, leading to the high fatality rate.
Immediate Actions taken
Immediately after the eruption, helicopters were used in conjunction with Japan’s Self-Defence Force soldiers to conduct a rescue mission at the summit (The Atlantic, 2014). At the bace of the mountain, 1000 firefighters, police officers and doctors treated those affected (Cyranoski, 2014). A 4km radius exclusion zone was also put up around the crater to prevent any further injuries or casualties. The actions taken were rapid and effective, exemplified by the 51 people they found in the days following the disaster (O’Conner, 2014). With regards to the initial number of personnel at the site, 1000 may have been too many, actually making the response slightly less efficient. In order for the authorities to execute the short term response in a more productive manor, fewer personnel should have been deployed but with more specialist training.
Actions taken in the weeks and months after the disaster
The short-term response to the Mt. Ontake eruption included ash, tephra, and vegetation being cleared off transport routes, airports resumed normal activities shortly after the eruption, and ski resorts, such as Ontake 2240, reopened two months later in early February 2015, once the 4 km exclusion zone was lifted (The Japan Times, 2015). These short-term responses were executed effectively and with due caution, as shown by the persistence of the 4km perimeter by the authorities to ensure the safety of locals, but evacuations of nearby areas could have also taken place in preparation for potential further eruptions.
Recommendations for the long-term
As a leading world economy, Japan is not economically hindered giving it an advantage when it comes to natural hazard protection, as one of the root causes of a nation’s vulnerability to natural hazards is economic limitation along with political and social instability (Wisner et al., 2003). There were relatively few monitoring instruments on Mt. Ontake, compared to other monitored volcanoes in Japan at the time (Cyranoski, 2014). This coupled with the high social loss stemming from the eruption would indicate that improved precautionary measures are required, thus I recommend the expansion of the systematic surveillance of all monitored volcanoes.
Additional monitoring methods should be applied to Japan’s most active volcanoes, such as those used to measure; gas release (Appendix 4.1), electrical conductivity of the ground (Appendix 4.2), and Temperature (Appendix 4.3) as these were not present on Mt. Ontake prior to the eruption, but have been placed on a select few other volcanoes around Japan. Whilst the process of better equipping volcanoes could be financially draining and time consuming, a trade-off between national finance and societal safety must be found, and this is possible, as Japan is very capable of overcoming economic barriers due to its financial strength (Lincoln and Gerlach, 2004).
The increased level of monitoring equipment would link well with the development of a global science syndicate. Due to the high frequency of volcanic eruptions each year, which is estimated to be around 50-60 (USGS, 2011), databases are constantly growing. The data that is taken from volcanoes around the world, such as GPS, tilt, and seismicity, are similar to what was being monitored on Mt. Ontake before the eruption. However, this information is not always shared globally. A coordinated science community focusing on volcanic activity, such as the International Council of Science (Appendix 5), could maximise scientific advances, better preparing countries for volcanic eruptions due to an increased ability to predict them (News Rx, 2017), thus reducing future effects of eruptions similar to that of Mt. Ontake (USGS, 2016).
The increase in shared data would also compliment the development of a more advanced volcanic forecasting system. Currently, volcanic forecasting uses data from monitoring devices to identify patterns which may indicate a volcanic eruption. There are limitations to this form of forecasting, as the monitoring data is not able to capture the diverse nature of volcanoes and their ability to change over time, which is one of the reasons the Mt. Ontake eruption was not foreseen. Therefore, an improved version of this method, based on models of physical and chemical processes, could be used in conjunction with the increase in surveillance to create more accurate eruption forecasts (News Rx, 2017). An example of this is the numerical weather prediction system (Appendix 6). An adaptation of this could be used with volcanoes to provide researchers with more accurate predictions of the size, duration, and hazards that could be associated with an eruption. However, this could be a difficult and time-consuming system to implement as it requires integrating different methods and data from lots of subject areas (News Rx, 2017), despite this, once put together the system would be far more effective at predicting future volcanic activity.
The integration of this forecasting technology with volcanic research could also aid in early warning systems. The Japanese government have also made plans to use more detailed and timely distribution of information regarding volcanic activity and create more hazard maps to work in conjunction with new evacuation plans (The Japan Times, 2015). The introduction of volcano early warning systems, such as the already established J-Alert system (Appendix 7), could give critical minutes to those who need to evacuate an area which is under threat from an eruption.
Finally, the increased reliability of early warning systems could prove to support the education and practice of disaster evacuation taught to both adults and children. Education around volcanic activity, aimed at the general public, can be used as a bottom up method of disaster prevention. Hazard preparedness can be taught in many ways from flyers, leaflets and hazard preparation courses for adults and for children; it can be taught in schools, where educational institutions already take part in initiatives to prepare children for earthquakes (Appendix 8). This form of defence against a disaster would integrate well into Japanese society as variations on disaster education has always been taught in schools in post-war Japan (Kitagawa, 2014), but as suggested in Appendix 8 the system may need some improving, which could be done by creating more time during the day for lessons on disaster preparedness, by elevating some of the emphasis on academia. This combination of national level and community level recommendations gives Japan the best chance of reducing the impact of future volcanic activity.
Appendix 1:
Volcanic Explosivety Index (VEI)
The volcanic Explosively index was invented by Chris Newell in 1982, and is comparable to the Richter Scale used to measure earthquakes. It is used to give the relative severity of volcanic eruptions using measurements such as volume of material ejected, height of the plume, and how long the eruption lasts. The scale has a range of 1 to 8 and is logarithmic, meaning that an increase of one represents an eruption 10 times greater than the number before. (NASA, 2017)
Examples of the VEI:
An index rating of 1:
– Has an ejecta volume of >10,000 cubic meters.
– Known as a Strombolian eruption.
– Is has plume height of 100-1,000 meters.
– Occurs very regularly with many eruptions in the last 10,000 years.
An index rating of 6:
– Has an ejecta volume of >10 cubic kilometers (10,000,000,000 cubic meters).
– Known as a Ultra-Plinian eruption.
– Is a huge eruption with a plume height of >30 kilometers.
– Occurs every 100 years with only 51 within the last 10,000 years.
(NASA, 2017)
Appendix 2:
Volcano Early Warning Systems
Fig. 2 Geowarn model, Early Warning System.
(GEOWARN, 2003)
The Geowarn model for volcanic early warning system is designed to fit any volcano hazard warning program. The system is designed to simplify the most significant transition of volcanic activity, which is from the green zone to the yellow zone, as shown in fig. 2. The transition represents the ignition of magmatic activity between the crust and the upper mantle which may eventually cause an eruption. The main focus of this model is provide an indication of when a volcano may have reactivated, which may give a host area the ability to prepare and install a monitoring network (GEOWARN, 2003). After the initial transition of green to yellow, further stages follow of orange and red which indicate what to do during the evolution of a volcanic eruption.
Appendix 3
3.1: Seismometer
Fig. 3.1 Seismometer.
(YourArticleLibrary, 2014).
A Seismometer is a device used to measure vibrations caused by earthquakes at various magnitudes. These vibrations are recorded on photographic paper and shows the beginning and end point of the vibrations, this is known as a seismogram (YourArticleLibrary, 2014). In the case of Mt. Ontake, the seismometers were used to identify seismic waves from up to 10km away (Cyranoski, 2014).
Figure 3.1 shows one form of seismometer, as there are many variations of this device. However, this version is used for recording the horizontal motion of the earth. This Seismometer arrangement uses an inertial weight, fixed with a pen, suspended just above the photographic paper drum, which is then attached to a support on the ground. When the frame of the seismometer moves, the weight records the vibrations on the paper relative to the motion produced by the Earth (YourArticleLibrary, 2014).
3.2: Tiltmeter
Fig. 3.2 Tiltmeter.
(Pacific Northwest Geodetic Array, 2008).
Tiltmeters are commonly used to measure ground tilt around volcanoes and fault lines, these often coincide as many volcanoes are situated on fault lines. Tiltmeters are very sensitive devices and are able to detect volcanic uplift to a factor of 1 part per billion, which is less than 1 inch in 16,000 miles (USGS, 2016). Tiltmeters are usually placed in boreholes to reduce to chance that they pick up any tilt produced by rainfall or thermal expansion. (USGS, 2016)
Like seismometers, there are several types of tiltmeters such as pendulum tiltmeter, mercury-pool tiltmeters, and bubble tiltmeter, etc. (Tilling, 1991). As these all these variations are slightly different it is not uncommon that multiple types of tiltmeters are put on volcanic sites to increase to likelihood of detecting any subtle earth tremors and seismic activity.
Appendix 4
4.1: Continuous sampling
Measuring the levels of sulphur dioxide that are escaping form the volcano can give an indication as to the probability of a volcanic eruption. An increase in this gas could be an indicator of a potential eruption but similarly a reduction in these gases could indicate a reduction in threat.
Continuous sampling is perhaps the most applicable method of monitoring to the Mt. Ontake eruption. This method analyses both short term episodes of gas expulsion (Minutes-Hours), and long term activity (Days-Years). With continual
Fig. 4. Device used in the continuous sampling of gas release on a volcano.
(Monitoring Volcanic Gases, 2010). advancements in technology these devices can be set up around vents, fumaroles, hydrothermal deposits, and solis and record findings which are then stored online or in another easily accessed location (Monitoring Volcanic Gases, 2010)
4.2: Electrical conductivity monitors
Changes in the conductivity of ground material can indicate varying levels of magma present underground. The electrical resistance of rock depends on the level of moisture in the ground as well as temperature. When there is an increase in magma underneath a volcano, the resistance of rock to electrical current decreases. By placing electrodes in the ground, it is possible to take measurements of electrical current in the ground, therefore tracking the movement of magma below the surface (Volcanic Hazards and Prediction, 2016).
4.3 Thermal Infrared Cameras
As magma begins to get closer to the surface, the temperature around a volcano increases, due to either the heating of groundwater or through the direct impact of the magma. These changes can range in their intensity, therefore an effective method of monitoring them is to apply a thermal imaging cameras (Volcanic Hazards and Prediction, 2016).
An example of this already taking place, is the Meteosat satellite which is 36,000 km above earth.
This satellite is already being used to monitor the Nyiragongo lava lake in the Democratic Republic of Congo. Onboard the satellite is the ‘Spinning Enhanced Visible and InfraRed Imager' (SEVIRI) which uses thermal cameras to observe the lava lake (Science News, 2014). It is thought that this technique can be applied to volcanoes all over the world, to help anticipate eruptions (Science News, 2014).
Appendix 5:
International Council for Science
The International Council of Science is an non-governmental organisation (NGO) that aims to bring together world science and allows everyone to benefit of accumulation of scientific information. The council have already amasses 142 countries and aims increase this figure (ICSU, 2017). The council have developed a plan which focuses on International research collaboration, science for policy, and universality of science, which they aim to achieve between 2012 and 2017 (ICSU, 2017). The aim of the ICSU is to make the global scientific community stronger as a whole to benefit society.
In order to do this they have tasked themselves with:
Being involved with issues that are most important to science and society
initiate communication between scientific groups around the world
To be neutral in terms of race, gender, political stance etc.
Appendix 6:
Numerical Weather Prediction
Numerical weather prediction uses mathematical models of the oceans and atmosphere to predict the weather based on current weather patterns (Haltiner, 1971). Numerical weather prediction uses observations form the present and applies them to computer models to forecast potential temperature, precipitation and many other elements of weather patterns, this process is known as data assimilation (NOAA, 2017).
Numerical weather prediction can be applied to volcanic eruptions as it is an advancement on the current forecasting system, whereby past and present data is gathered and amalgamated on the volcano in question, constructing models and predictions based on this progression of data captured from that volcano.
Appendix 7:
J-Alert
The J-Alert system was launched in February 2007 by the Japan Fire and Disaster Management Agency (FDMA). This system uses satellites to broadcast alerts, it is currently working as an early warning system in Japan and In the case of a tsunami, earthquake or ballistic missile, is able to inform citizens via a system of loudspeakers (Centre for public impact, 2016).
It reportedly only takes 1 second to let officials know about impending threats and 4 to 20 seconds to also pass the message on to citizens, making the it the worlds fastest early waning system (Cyranoski, 2014). The warnings that are broadcast for these disasters are in 5 different languages ‘Japanese, English, Mandarin, Korean and Portuguese’ (Centre for public impact, 2016).
The J-Alert system as only malfunctioned once in the form of a false alarm to recent missile strikes by North Korea, which shows the reliability of the system.
The Objectives of J-Alert are:
Spread awareness of disasters
Provide communities with updates of occurring disasters
Give information about evacuation and shelter during and after a disaster
Appendix 8:
Earthquake Disaster Education
Earthquake disaster has long been taught in schools in Japan due to the volatility of the area, however, ‘It is difficult to say that current school disaster education in Japan is adequate’ (Japanese School Disaster Education, 2007). Most schools in Japan only undertake evacuation drills twice a year and few are teaching advanced disaster prevention, which includes, exploration, mapping, building inspections, etc. A contributing factor to the lack of disaster education was the announcement of the programme for international student assessment (PISA) which puts a large emphasis on Academia reducing available time for education of disasters (Japanese School Disaster Education, 2007).
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