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Volume 13 | Issue 33 | Number 6 | Article ID 4359 | Aug 17, 2015 The Asia-Pacific Journal | Focus

Volcanic as Components of Complex Systems: The Case of Japan

Gregory Smits

The past year or so has been a time of the ’s crust suggested Mt. Fuji is more particularly vigorous volcanic activity in Japan, likely to erupt owing to effects from the 2011 or at least activity that has intruded into public Tōhoku .3 Well publicized by a press awareness. Perhaps most dramatic was the release on the eve of its publication, mass deadly eruption of Mt. Ontake on September media around the world have reported this 27, 2014, whose 57 fatalities were the first finding, along with speculation regarding -related deaths in Japan since 1991. On possible connections between and May 29, 2015, Mt. Shindake, off the southern volcanic eruptions. tip of Kyushu, erupted violently, forcing the evacuation of the island of Kuchinoerabu. That As of June 30, 2015, the Japan Meteorological same day, , located just north in Agency (JMA) designated ten volcanoes in or , erupted more forcefully than near the main Japanese islands as warranting usual. Sakurajima has been erupting in some levels of warning ranging from Mt. Shindake’s fashion almost continuously since 1955, but Level 5 (“Evacuate”), to Level 2 (“Do not since 2006, its activity has become relatively approach the crater”) in seven cases. more vigorous. Indeed, a May 30 Asahi shinbun Sakurajima is at Level 3 (“Do not approach the article characterized these eruptions as “the volcano”), as is Hakoneyama, located near Mt. latest ominous sign that the Earth’s crust Fuji. Despite often-sensational reports about around the archipelago is getting restless.” The Mt. Fuji, it is not currently on the JMA volcanic article argued that the twentieth century was warning list.4 an anomaly in that volcanic activity throughout Japan was relatively subdued, whereas the The aftermath of 3/11 awakened many in Japan more vigorous activity of recent years is closer and around the world to the dangers of to the long-term normal pattern.1 seismicity and nuclear power. Even if the magma beneath the Japanese islands had not Warnings of an impending eruption of the long- been so active in recent months and years, it is dormant Mt. Fuji have been commoninevitable that volcanic hazards would also throughout the years of the twenty-firstenter the public discourse on nuclear power century. After the March 11, 2011 and preparedness. Nuclear (hereafter “3/11”), the frequency ofpower, of course, generates an ideological hypothesized imminent eruptions of Mt. Fuji opposition that runs deeper than any specific increased. For example, retired professor safety claims. Paul Lorenzini, argues that this Kimura Masaaki, known for making grandiose ideological opposition to nuclear power is a predictions about earthquakes and volcanic manifestation of mistrust of modern institutions eruptions, published books on Mt. Fuji’s and mistrust of “the values of modern Western eruption (already underway according to society that these institutions embody, Kimura’s claims) in 2011 and 2112.2 Especially particularly their capitalist economics and their influential was a short July 2014 article in the reliance on science and technology.”5 In this journal Science. This study of perturbations of view, failures by relevant state institutions to

1 13 | 33 | 6 APJ | JF predict and substantially mitigate deadly or ash.”10 I explain these volcanic hazards in a destructive natural hazards can serve as later section. evidence that the state cannot be trusted to safeguard nuclear power. Because they are For many, the simple fact that Japan is serious natural hazards, it is possible to link vulnerable to a range of natural hazards such events like the unpredicted eruption of Mt. as earthquakes, , volcanic eruptions, Ontake and anticipated events like the eruption and is sufficient to argue against of Mt. Fuji to the Fukushima disaster and to nuclear power. However, looking at the matter nuclear power.6 in a more focused manner, linking the hypothesized near-term eruption of Mt. Fuji A 2013 Mainichi shinbun survey of with a nuclear disaster requires a considerable regarding volcanic hazards and stretch of the imagination. To be sure, a major nuclear power plants asked which plants are at eruption of Mt. Fuji would probably cause risk. The experts mentioned the Sendai plant in considerable social and economic dislocation, most often. Of the 50 and it might be deadly. Moreover, the Hamaoka survey respondents, 29 specified that the nuclear plant is at great risk for seismic and Sendai plant was at risk and 19 were opposed damage, particularly if the great Tōkai to its restarting. By contrast, six respondents earthquake and tsunami, which many Japanese mentioned Hamaoka in Shizuoka Prefecture, have feared as imminent since the 1970s, does the closest plant to Mt. Fuji (and toin fact happen more or less as imagined. Mt. Hakoneyama), as being at volcanic risk and two Fuji, however, is less likely to pose a serious opposed its reopening. One other significant nuclear risk. In Kyushu, on the other hand, the point about this survey of experts is that 12 of proximity of Kagoshima’s Sendai Nuclear the 50 did not list any plants, and nine Power Plant to Sakurajima and other active specifically stated that no plants were at risk. volcanoes that are part of the Aira (a Based on this survey, a majority of expert vast pool of magma) almost certainly does opinion puts volcanism in southern Kyushu constitute a major nuclear risk as well as a risk high on the list of risk to nuclear plants, but a for other forms of damage to the entire region significant number of experts do not regard of southern Kyushu. Indeed, most of the volcanic hazards as a serious threat to nuclear articles in the scientific or popular press linking power plants at all.7 English-language media volcanism in Japan to nuclear hazards sensibly widely reported select results of the survey.8 focus on Sakurajima and the Aira Caldera.11

According to another recent assessment (circa While acknowledging the importance of 2009), “virtually all operating nuclear power volcanism as a to nuclear power, it is plants in Japan are potentially threatened by not the aim of this article to discuss this topic the possible harmful impacts of fallout, in detail. Similarly, it is not my goal here to channelized distal lava or mudflows, ormake predictions or to assess risk. Instead, I tsunami. The phenomena may easily impact advance the argument that volcanic hazards sites tens of kilometers or even hundreds of interacting with societies results in a kilometers from the erupting volcano.”9 In complex system. Here I use “complex” system addition to manifesting itself as a range of in a technical sense, which I explain in the final physical hazards and possibly disrupting section. If indeed, volcanic hazards interacting electrical and cooling systems, with society constitute a complex system, then “might transport radionuclides, either as the only way to mitigate these hazards particles incorporated into tephra fragments or effectively in is to use complex systems theory. as compounds absorbed into the surfaces of In short, I introduce complex systems theory in

2 13 | 33 | 6 APJ | JF the context of volcanic hazards in Japan. earth’s heat comes from nuclear fission from radioactive elements within the asthenosphere With this argument in mind, this article has two and deeper.12 In the future, we might develop main goals. First, rather conventionally, I better ways of exploiting this natural nuclear explain the basics of volcanism and survey the energy. range of typical volcanic hazards. In addition simply to conveying information, this survey of volcanoes is intended to suggest the wide range of variables at play in the realm of alone. With that background in place, I make the case that volcanic hazards are part of a complex system. Finally, I briefly explain complex systems theory, and I propose a general approach to modeling the volcanic hazard-plus-society system. One point of the whole discussion is to introduce a way of thinking about volcanic hazards that is likely to be unfamiliar to many readers. The geographical focus is Japan and the particular natural hazard is volcanism, but many of the points here are applicable to other societies Figure 1. Structure of the earth. and to other types of natural hazards. ("Earth poster" by Kelvinsong - Own work. Licensed under Creative Commons Attribution-Share Alike 3.0 Volcanoes and Volcanism via Wikimedia Commons).

Beneath its usually calm surface, the earth is a living planet. It consists of several distinct In addition to heat from radioactivity, heat from layers defined by their composition. From the the molten iron outer core of the earth helps innermost layer of the earth moving outward is warm the mantle. The heat from the core the inner core, the outer core, the mantle, and passes through the mantle, which effectively finally, the crust. Although the entire mantle is transfers this heat toward the surface via similar in composition, it is subdivided into two convection currents in the asthenosphere. zones based on its physical properties. The These convection currents probably contribute upper part of the mantle is rigid, like the crust, to tectonic plate movement, although details of and the upper mantle and crust together the mechanism remain speculative. Combined constitute the lithosphere. The interior part of with plate movements, mantle convection the mantle, although not liquid, is softer and enables the surface of the earth to radiate ductile (flexible). This ductile zone is the approximately as much heat as it receives from asthenosphere. The earth’s surface consists of the nuclear reactions within it. Moreover, a patchwork of tectonic plates. Except in convection also moderates temperatures in the certain zones where plate collisions peel away mantle, keeping them low enough to prevent the crust from the upper mantle, tectonic plates consist of rigid crust attached to the widespread melting. However, localized rigid outer layer of the mantle. melting does occur. This localized melting produces the molten rock—called magma when The living earth moves in a variety of ways, and it is below the surface and lava when it is this movement requires heat. According to above—which sometimes erupts through recent studies, approximately half of the openings in the surface known as volcanoes.

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The basic definition of a volcano is simply any known hot spots are exceptions to the general place where magma has reached the surface of rule of gentle eruptions. The magma under the earth at any point in the past. It is Yellowstone National Park in the United States important to bear in mind, therefore, that is a silica-rich granitic magma called , volcanoes occur in a wide range of types and with the potential for causing an explosive geologic circumstances. eruption that would be a worldwide catastrophe. The hot spot under Iceland exists It is worth noting that the geothermal heat that near plate margins, and the eruptions of its creates volcanoes also constitutes a vast, and volcanoes tend to be relatively explosive. largely untapped, source of energy. Iceland produces approximately 30% of its electricity Volcanoes formed at the edges of subduction from geothermal energy (Japan, less than 1%). zones, however, are usually the creations of relatively andesitic magmas. Andesitic magma Lava, gas, and other products of volcanic is more viscous (thicker) than basaltic magma eruptions have created approximately 80% of and usually contains a relatively high volume of the earth’s surface and much of its atmosphere. gas. Most volcanoes in Japan ore of this type. Today there are over 1500 active volcanoes Eruptions of these volcanoes tend to be around the world. There are several ways of infrequent and explosive, emitting large classifying volcanoes, but even volcanoes in the quantities of volcanic ash when they do erupt. same category vary widely regarding the The 1980 eruption of Mt. St. Helens and the details of their activity and their potential to 1991 eruption of Mt. Pinatubo are examples of create natural hazards. Most active volcanoes explosive volcanic eruptions. Sakurajima is a are located at the boundaries of tectonic plates. complex case because it is apparently fed by However, approximately 100 “hot spots,” two magma chambers, one basaltic and one roughly 15 of which are active, exist in andesitic. Owing to changes in the underlying apparently random locations, often in the stable geology, Sakurajima’s magma mixture is interior of plates. For reasons not entirely becoming more andesitic.13 understood, hot plumes of molten rock rise through the mantle to create most of these hot Even setting aside the human built spots. In many cases, the molten rock does not environment, there is wide variability in the quite reach the surface, resulting in undersea real or potential degree of hazard volcanoes volcanic islands known as seamounts.pose. Dissolved gas is perhaps the most Sometimes hot spots produce volcanic islands important variable. vapor is the most such as the Hawaiian Islands. The string of common gas associated with magma, with Hawaiian Islands and seamounts traces the carbon dioxide, sulfur, chlorine, fluorine movement of the Pacific Plate across a hot spot making up most of the rest. Taken together, over the course of roughly 70 million years. these gasses are called “volatiles.” An eruption will generally be more explosive and hazardous Volcanoes in the Hawaiian Islands are typical of when the viscosity of the lava is too high to those created by hot spots. The magma is allow volatiles to escape gently or if the volume relatively basaltic, which for our purposes of dissolved gas is extremely high. The gas means that it is of low viscosity. The low tends to propel lava into the air in the form of viscosity enables dissolved gas to escape ahead small to medium pieces of rock commonly of the magma. Therefore, eruptions ofcalled “bombs” and, especially, as volcanic ash. Hawaiian volcanoes and most others formed by basaltic magma are rarely explosive, except Strictly speaking, volcanic “ash” is not really when magma meets . Two well- ash because it is not the product of combustion.

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Volcanic ash is fine shards of magma ejected into the air, and its physical characteristics are quite different from the ordinary ash produced by fire. If, for example, you happen to be driving an automobile through the aftermath of an eruption and the windshield becomes covered with volcanic ash, do not turn on the wipers. Doing so would be like scraping abrasive sandpaper across the windshield. Volcanic ash in various manifestations constitutes a major natural hazard, as I will explain in detail. Figure 2. Plate tectonics and volcanism.

We have seen that volcanoes occur most ("Tectonic plate boundaries" by Jose F. Vigil. USGS - commonly at or near the boundaries of tectonic [1]. Licensed under Public domain via Wikimedia Commons) plates. Generally, volcanoes at the boundaries of diverging plates—undersea volcanoes at ridges, for example—produce basaltic The source of magma in subduction zones is magmas, low in volatiles, that erupt effusively, the edge of the downward-moving oceanic plate not explosively. Our concern is not with that eventually melts into the mantle as it volcanoes at diverging plate boundaries but descends. Friction from moving rocks can with volcanoes in subduction zones. generate heat sufficient to liquefy them. The subduction process drives trapped seawater A subduction zone is the area near the out of the sinking edge of the plate, and this boundaries of converging tectonic plates. hot steam can produce magma through a Oceanic crust is thinner and denser than process known as hydration melting. Moreover, continental crust. Therefore, plates whose the composition of the crust is such that it leading edge is oceanic crust will subduct (push melts at a lower temperature than the mantle underneath) the edge of a plate consisting of of the asthenosphere, and melted crust is continental crust. Japan is at the junction of another source of magma in subduction zones. four tectonic plates, and nearly the entire The result on the surface of the earth is a line Pacific side of the country is subject to the of volcanoes near the coast on the overriding geological processes and hazards associated continental plate, parallel to the ocean trench with subduction zones. Earthquakes and marking the point at which the subducting tsunamis caused by sudden slippage of the plate meets the continental plate. Another subducting plate are the most common such common result of this process is the hazard, and explosive volcanic eruptions are introduction of large quantities of volatiles into another. the magma, thus increasing the hazard potential.

In the case of Japan, the Nankai Trough extends offshore from Kyushu northward to near the Bōsō Peninsula. This trough is the result of the Philippine Sea Plate pushing under the Eurasian Plate. The Pacific Plate pushing under the North American Plate creates the Japan Trench, whose movement caused the

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2011 Tōhoku earthquake. Although particularly subterranean environment. Fracking (hydraulic known for their ability to generate megathrust fracturing)-induced earthquakes are one earthquakes and destructive tsunamis, these example, as is shaking of the ground caused by subduction zones have also created Japan’s the movement of magma. We can call the latter many volcanoes. volcanogenic earthquakes. As a whole, volcanogenic earthquakes (and other non- Seismicity and Volcanism tectonic earthquakes) tend to be less powerful than tectonic earthquakes and do not constitute Volcanic activity coincides with earthquakes in a major natural hazard. As we will see, many parts of the earth, including Japan. however, volcanogenic tsunamis can be a major Moreover, the same basic geologic activity, natural hazard. subduction of tectonic plates, is the source of both seismicity and the volcanism in the The dominant theory of earthquakes in Japan relevant regions. It is common to assume, from approximately the seventeenth century therefore, that some causal relationship must into the modern era was that accumulations of obtain between seismicity and volcanism. warm or hot (yang) energy within the earth Indeed, most of the discourse since 2011 on caused shaking by exerting upward pressure. Mt. Fuji’s impending eruption hypothesizes that This view easily linked both seismicity and the Tōhoku earthquake has played a role in volcanism via a single causal mechanism, a link making the volcano more dangerous. reinforced by the proximity of volcanic Nevertheless, as of now there is no widely eruptions and earthquakes. This understanding accepted, comprehensive theory of the of earthquakes as explosive events caused by relationship between seismicity and volcanism. accumulated pressure within the earth One basic classification of earthquake types is persisted well into the twentieth century. One tectonic versus non-tectonic earthquakes. effect was to perpetuate the belief that Tectonic earthquakes are the result ofseismicity and volcanism must be closely accumulated strain in crustal rock causing a connected. fault plane to fracture. In rare cases in which A typical example is a 1915 article that the fault surface contains no irregularities, thus appeared in the Yomiuri shinbun. The article’s keeping friction low and allowing smooth content derived from a presentation by the sliding, the movement of the earth is aseismic. seismologist Imamura Akitsune (1870-1948). It The vast majority of fault plane ruptures, affirmed the popular lore claiming major however, are seismic. In other words, accumulated strain overcomes friction, sending earthquakes occur in approximate 60-year shock waves (seismic waves) through the earth. intervals, based on the old zodiac cycle. A Tectonic, seismic earthquakes are what we statistical analysis of past earthquakes, typically call “earthquakes.” They range from Imamura pointed out, indicates that there was events so minor as to be imperceptible except some basis to the idea. Moreover, major by the most sensitive instruments to magnitude volcanic eruptions tend also to follow a sixty- 9 class events such as the 2011 Tōhoku year cycle. As was common at the time, the earthquake, so powerful that it slightly shifted article posited a direct link between the two the earth’s axis. geological processes. It claimed that insofar as each phenomenon releases energy, volcanic Non-tectonic earthquakes also occur. Examples activity keeps earthquakes mild and vice-versa. include shock waves from an underground The relative prominence of each type of nuclear blast or shock waves created when geological activity alternates, thus producing rock shifts because of changes in thesomething more like a 120-year cycle.14

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Similarly, observers of Japanese earthquakes volcanism. A tectonic earthquake often reported balls of fire or other forms of may set off an eruption that would fire, heat, or light emerging from the earth have happened eventually anyway, either just before or during an earthquake. For but is not going to create a new example, in an official report on the Great volcano or produce a magma Kantō Earthquake of 1923, meteorologist supply where none previously Fujiwara [Fujiwhara] Sakuhei (1884-1950) existed. In marked contrast, reported at length on a great ball of fire rising volcanogenic earthquakes are into the air at a 15-degree angle from the consequences, rather than causes, Nikolai (Holy Resurrection) Church in of eruptions and of the magma 15 Surugadai. The details need not concern us, movements leading up to but such sightings were conceptually possible eruptions. They are not so in part because of the assumption of a close powerful as tectonic earthquakes link between seismicity and volcanism. As and can usually only be felt (if at knowledge of both phenomena increased all) only close to the volcano.17 dramatically during the 1960s, many specialists no longer regarded volcanism and seismicity as directly linked to each other, but rather as the The assessments of Shimamura and Rothery results of a geology based on tectonic plates agree that there is no known mechanism and their movements. directly linking seismicity and volcanism.

In a book for general audiences, seismologist Magma can rise to the surface only if it is less Shimamura Hideki titled one short chapter with dense than the surrounding solid rock, and the question, “Is there a connection between density is therefore the most important factor the activity of volcanoes and earthquakes?” His in the buoyancy of magma. Other conditions reply begins, “Earthquakes and volcanoes are that control the flow of magma include the both phenomena originating under the earth’s precise composition, which often changes as surface, so there must be some kind of magma moves, viscosity, and the physical connection between them, but unfortunately structure and characteristics of the rocky contemporary science is not able to say what conduits through which magma moves or in that is.” He then discusses several examples of which it collects. Whether, when, and in which eruptions occurring soon after earthquakes. In manner a volcano erupts is a function of the 1707, Mt. Fuji erupted 49 days after the local details of each volcano. Often chambers of massive (estimated M8.4) Hōei earthquake. magma exist in a delicate balance such that a Nine months after the 1604 Keichō earthquake, small change in relevant parameters might Hachijōjima erupted. Shimamura concludes allow magma to come to the surface or prevent that it is “not strange” that earthquakes might 16 it from doing so. It is with respect to his point trigger eruptions and vice versa. that the seismic waves of tectonic earthquakes might alter significantly the local details of a In a textbook, David Rothery particular volcano, typically by changing the explains similarly, distinguishing between physical conditions of a volcano’s internal tectonic and volcanogenic earthquakes: “plumbing.” Currently, it is not possible to make general statements about the effects of Apart from occasionally, triggering seismic waves on volcanic structures, nor is it an eruption there is no possible in individual cases to predict changes straightforward link between in future volcanic activity owing to the possible [tectonic earthquakes] and influence of seismic waves. The key point for

7 13 | 33 | 6 APJ | JF our purposes is that although both thewithout a summer.” There have been no VEI 8 seismicity and the volcanism affecting Japan eruptions during the past 11,700 years (the are byproducts of plate tectonics, they are best Holocene epoch), but there is strong evidence regarded as separate phenomena. for several such eruptions during a period ranging from roughly 25 thousand-27 million VEI and other Volcanic Metrics years ago. Several of these VEI 8 eruptions took place in the region of today’s Yellowstone As with earthquakes, specialists have National Park. What would be the developed metrics for some of the major consequences of a future VEI8 eruption in characteristics of volcanic eruptions. To some Japan? It is not too much to imagine a re-boot degree, these metrics are related to the for the whole enterprise of human and potential destructiveness of an eruption, that is, life on earth. of its severity as a natural hazard. The extent to which this potential will actually manifest itself The geological history of the Japanese islands as a natural disaster, however, is an emergent includes several VEI 7 eruptions. Volcanoes phenomenon not directly predictable from the capable of producing VEI 7 or VEI 8 eruptions simple behavior of individual elements in the are commonly called “supervolcanoes.” Japan is natural-social matrix. In other words, the home to three VEI 7 class supervolcanoes or process whereby a natural hazard intersects volcanic . One is the Kikai Caldera with human society, especially, but not limited under the , one is Mt. Aso in to the built environment, constitutes a complex Kyushu’s Kumamoto prefecture (which erupted system in the technical sense (as opposed in late November 2014), and the third is the simply to being complicated). I will return to Aira Caldera, of which Sakurajima is a part. this point in the final section. It is important to emphasize that the VEI scale In the case of volcanoes, explosive eruptions are particularly hazardous. The Volcanic does not say anything about the actual Exclusivity Index (VEI) ranges from 0 to 8. It is deadliness of an eruption. For example, there a function of two variables. The first is the were no known fatalities resulting from Mt. volume of fragmented material erupted (in Fuji’s 1707 VEI 5 eruption. By contrast, the VEI cubic meters), and the second is the height of 0 collapse of Mt. Unzen in 1792 the eruption column (in kilometers). Most resulted in approximately 14,300 fatalities. As Japanese volcanic eruptions fall within the VEI with earthquakes, the deadliness of volcanic 2-4 range, releasing between 106-109 cubic eruptions depends on the interaction of a meters of fragments, with eruption columns complex array of variables. ranging from 1 kilometer to 25 kilometers in height. The magnitude of a volcanic eruption is a measure of the total mass of ejected material, The 1598 and 1783 eruptions of Mt. Asama are and the known range is from 0 to 8. In the case estimated at VEI 3 and 4 respectively, and the of explosive eruptions, eruption magnitude and estimate of Mt. Fuji’s 1707 eruption is VEI 5. VEI are similar. A third measure of eruptions is The 1914 eruption of Sakurajima in Kagoshima intensity, which is the peak rate at which was VEI 4. The eruption of Mt. St. Helens in material erupts. The highest known rating is 1980 was VEI 5, and that of Mt. Pinatubo in 12, corresponding to one billion kg/second of 1991 was VEI 6. In 1815, a VEI 7 eruption of erupted material. These measurements can be Tambora in Indonesia resulted in roughly useful for certain types of classification. 60,000 fatalities and altered worldwide climate However, in assessing the degree of danger a for years. Indeed, 1816 became the “year particular volcano may pose, it is necessary to

8 13 | 33 | 6 APJ | JF consider a range of possible volcanic hazards , and this cascade of falling debris as they are likely to play out in local conditions. accounted for most of the fatalities. A debris The following section is a survey of the most avalanche also killed about 400 in connection common types of volcanic hazards relevant to with the 1888 eruption of Mt. Bandai in Japan and many other subduction zone areas Fukushima Prefecture. Large quantities of such as the Pacific Northwest of the United debris often accumulate on the sides of States. volcanoes, and they constitute a potentially severe hazard when populated areas are within Volcanic Hazards: Lava, Pyroclastic Flows, range of a possible avalanche. Heavy rain or Debris , , Ash, Tsunamis other non-eruption events can trigger debris avalanches, and it is possible in some cases The first volcanic hazard that probably comes that the disruptions caused by an avalanche to mind for many is lava flows. Lava usually could trigger an eruption. flows so slowly, however, that it is the least deadly of the volcanic hazards. Moreover, A third type of dangerous flow is a , a flowing lava is more typical of the basaltic lavas volcanic mudflow, which usually follows of Hawaiian-style eruptions, not the explosive topographic channels. The mud in this case is eruptions common in Japan and other mainly ash mixed with water, but other subduction zones. materials can contribute to the slurry. A common scenario is that the eruption melts a Explosive eruptions can produce pyroclastic volcano’s cap. Lahars are deadly. They flows. Sometimes called an ash flow, a consists of a mass of various travel fast and far, and require as little as 10% ejected debris that behaves like a liquid moving water to remain mobile. As a lahar travels rapidly. Often a rapidly moving cloud of gas through a valley or other channel, it picks up and debris (called nuée artente) accompanies a additional material. In this way, some lahars pyroclastic flow. These flows can be extremely have the potential to do great damage a long lethal. In 1902, for example, Mt. Pelée on the distance from the site of an eruption, French Caribbean island of Martiniqueparticularly if they burst out of the confines of a erupted. On the morning of May 8, avalley. In 1985, for example, a lahar in pyroclastic flow traveled the 6 kilometers from Colombia from the Nevado Del Ruiz volcano the volcano to the town of St. Pierre, and wiped wiped out the town of Armero, which was 65 it out, killing all but one of its 28,000 residents kilometers distant. Over 23,000 of Armero’s and even capsizing or de-masting ships in the residents perished. Another key feature of this harbor. Pyroclastic flows have accompanied tragedy was that the eruption itself was not many eruptions of Japanese volcanoes such as particularly large or severe. The presence of a Mt. Fuji in 1707, Mt. Asama in 1783, and Mt. large ice cap on the volcano and the location of Unzen between 1990 and 1996. The collapse of Armero in a river valley that passed near the a magma dome is a common cause ofvolcano were the main factors in this case. pyroclastic flows. Some pyroclastic flows Lahars entering rivers can cause massive (pyroclastic density currents) contain sufficient flooding and thus potentially endanger facilities energy to flow over topographic barriers that located near rivers, even when far from an might be expected to contain or stop most active volcano. currents of material. Changes in the built environment can also be In 1792, Mt. Unzen killed over 14,000 people, significant insofar as they change topography. but not because it erupted. Instead, the For example, the City of Seattle website points collapse of an old lava dome generated a debris out that there is no evidence of a lahar from

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Mt. Rainier reaching the present location of the cold air makes the ash-turned-to-glass become city during the past 10,000 years.brittle and shatter, thus allowing the engines to Nevertheless, in light of modern development re-start. The spring 2010 eruption of the of the region, it is impossible to say that Seattle Icelandic Eyjafjallajökull disrupted air traffic is now out of range.18 Because any type of for months. volcanic flow plays out according to local topography, historical data can only serve as a rough guide for future possibilities in developed countries.

Heavy rain can liquefy deposits of unconsolidated volcanic ash and cause a lahar. In some circumstances, these rain-induced lahars can persist for years. In 1998, a hurricane-induced lahar in Nicaragua entirely wiped out two small towns. Japanese volcanoes are subject to Lahars. One relatively recent example is Mt. Unzen. This video shows footage from three different lahars in Japan, beginning with Mt. Unzen in 1993:

Notice that volcanic ash (often called tephra) plays a major role in the volcanic hazards described thus far. Insofar as it enriches soil, volcanic ash can be beneficial. In many other Figure 3. Diagram of a Vulcanian eruption. Key: 1. respects, however, volcanic ash is a serious Ash plume 2. Lapilli 3. Lava fountain 4. Volcanic ash hazard. Depending on circumstances, ash can rain 5. Volcanic bomb 6. Lava flow 7. Layers of lava travel far from its point of origin. Precipitating and ash 8. Stratum 9. Sill 10. Magma conduit 11. onto the ground, ash can damage plant and 12. Dike.

animal life and thereby alter the natural or ("Vulcanian Eruption-numbers" by Sémhur (talk) - agricultural environment. Suspended in the air, Own work, from the document about volcanism on ash can effect climate. More acutely, clouds of the Portail sur la prévention des risques majeurs volcanic ash are a threat to aviation. The ash (web portal about the prevention of the major risks) of the Ministère français de l’Ecologie, du clouds look like ordinary atmospheric vapor Développement et de l’Aménagement durables clouds and are difficult to detect. The abrasive (French Minister of the Ecology, Environment and ash damages turbine engines, often turning to ). Licensed under Creative glass inside them and shutting them down. Commons Attribution-Share Alike 3.0-2.5-2.0-1.0 via Wikimedia Commons) Over 100 encounters between aircraft and volcanic ash have taken place, some of which resulted in the shutdown of all engines. Despite some very narrow escapes, all such flights Volcanoes can erupt underwater. Moreover, ended with successful emergency landings volcanically induced debris avalanches, after some of the engines were re-started. , or pyroclastic flows have the When pilots realize they are in a volcanic ash potential, in some circumstances, to displace cloud, the basic procedure is to cut back on the enough water to generate tsunamis as engines and glide out of the cloud. The rush of destructive as those generated by megathrust

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(subduction zone) earthquakes. The 1883 VEI 6 eruption of Mt. Fuji were it to happen eruption of Krakatau in Indonesia generated tomorrow? I am not in a position to say with tsunami waves that killed over 30,000 along the any certainty. Most likely, variables such as coasts of Indonesia and Sumatra. Volcanoes warning period (if any) preceding the eruption, and the areas around them are often unstable, size, duration, and other parameters of the as we have seen in the example of rain-induced eruption, wind patterns, the robustness of key lahars. Therefore, an eruption is not necessary. elements of infrastructure, the of The 1792 collapse of the old lava dome in Mt. political and administrative responses, and Unzen generated a tsunami that killed nearly many other factors will interact to produce an 15,000. outcome that is nearly impossible to predict. This outcome will emerge from the interaction Volcanic Hazards as Part of a Complex of these many parameters, variables and social System and natural agents. In other words, an event such as a major eruption of Mt. Fuji within the Throughout the current century, Mt. Fuji has broader context contemporary Japanese been on the verge of erupting, according to society, unfolding over time, constitutes a mass media articles, some scientific papers, complex system. Complex systems theory, a and the blogosphere. Particularly in light of rapidly developing field, seeks to Japan’s recent experiences with naturalunderstand—and possibly to influence—such , such reports about Mt. Fuji often systems. feature a sensational tone.19 Although some types of volcanic eruptions can be predicted The roots of complex systems theory extend to fairly well in the short term, after classic signs a seminal 1948 paper by Warren Weaver, who of magma movement begin, there is no way to wrote of a “middle region” of “organized know when Mt. Fuji will begin to manifest complexity” in between the simple two-variable measurable signs of an eruption. The event problems common before 1900 and the could begin tomorrow, or it could happen unlimited-variable probability based problems centuries from now. In this sense, volcanic of the early twentieth century such as eruptions are as unpredictable asthermodynamic laws, actuarial tables, or earthquakes.20 Similarly, given the vastanticipating traffic along phone networks.21 differences in the physical and socialWarren’s paper laid out the general intellectual topography compared with 1707, the historical agenda, and advances in computing power record of that earlier eruption is of little use in provided the means for the emergence and planning for the present and future. That past development of the interdisciplinary field of event does underscore the near certainty of complex systems theory in the 1970s. large quantities of volcanic ash blanketing the Tokyo metropolitan area. Although unlikely to There are several different categories of be a direct cause of many fatalities, a major complex systems. Because the field of complex eruption of Mt. Fuji would likely be severely systems theory is so new, there tends to be disruptive. Major transportation hubs would some overlap between these categories. likely shut down, and large portions of modern Natural hazards interacting with human infrastructure would be subject to damage or societies constitute a multi-agent system destruction from ashfall. (MAS). Numerous interacting elements, usually called “agents,” comprise such a system. Some Is Japan as a whole and the Tokyo region in agents are passive (no goals, no volition), particular ready and able significantly to others are active in a simple manner (e.g., an mitigate the damaging effects of a major instinct in an animal), and others are active in a

11 13 | 33 | 6 APJ | JF complex manner (e.g., human motives). The to tune the model. interaction of any subset of agents typically affects the system as a whole in ways that are There are many shortcomings of agent-based often difficult to predict. In this sense,modeling, and I do not intend to present it as a phenomena “emerge” from such systems. panacea. Even the most sophisticated models Emergent phenomena are a classic indicator of fall short, often far short, of simulating the complex systems. It may also be possible to complexities of the real world. Not only is it classify complex systems created by the often impossible to include all the relevant interaction of natural hazards and human agents in a model, but the behavior rules societies as complex adaptive systems (CAS), assigned to agents are typically very simple. examples of which include, the immune system, Moreover, creating truly useful models would and ecosystems. The key point for our purposes require considerable time, resources, and, is that whether regarded as an MAS or CAS, an mostly likely, extensive collaboration between important tool for comprehending the behavior academic, industry, and government entities. of natural hazards interacting with societies is Any insights tentatively gained from agent-based modeling. sophisticated modeling efforts would need to be compared with real-world data in an effort Simply stated, agent-based modeling attempts better to tune the models. In short, a serious to gain insights into the behavior of complex effort to construct useful agent-based modeling systems, especially the impact of specific for natural disaster scenarios would be a large- agents (or variables such as population density) scale endeavor, it would likely take years to on the system as a whole. Such modeling seeks come to any fruition, its results would be to identify the relevant agents and assign imperfect, and insights gained from modeling behavior rules to them. Agent-based modeling would require careful translation into plain typically takes into consideration the broader language and key points for use in most environment, issues of scale (often called political and administrative settings. “granularity”), adaptation or learning rules, and, in the case of active agents, decision- I should also point out that government making heuristics. Such modeling seeks to agencies and industries frequently employ understand the big picture, as opposed to other kinds of models to deal with smaller sets solving narrowly focused pragmatic problems of variables and to solve specific problems.22 common in fields such as engineering. A better Modeling is hardly new, but agent-based (though typically never complete)modeling of natural hazards and disasters has understanding of the big picture can be useful been minimal. Although not exhaustive, my own in allocating resources, creating contingency searches have turned up only a few narrowly plans, and formulating policy. In the case of focused models. The demands of academic volcanism and other natural hazards, effective publishing tend to mitigate against bold, big- modeling might permit better insight into how picture projects, and what I have proposed the behavior of key agents would play out in here is certainly ambitious for many reasons. different scenarios. After a model is created, it Despite the imperfect nature of even the most can be run on computers repeatedly. Such sophisticated models, they are the only tool we repetition can permit the application of the presently have to understand complex systems usual statistical metrics. Moreover, once the and thus develop better strategies for dealing model is set up in software, it becomes possible with them. easily to modify the behavior of any key agent or variable and re-run the simulation. New To illustrate this modeling process, let us experimental or observational data can be used return to Mt. Fuji. Suppose we were to create

12 13 | 33 | 6 APJ | JF an agent-based model for a major eruption in problems. Notice that differences in random 2015. To keep this illustration manageable, let variables and starting conditions can result in us focus only on one hazard: volcanic ash. significantly different impacts, a classic sign of Moreover, as this hazard plays out over time, a complex system. my illustration includes only a subset of the possible agent interactions. For the purposes of modeling, we would need to identify the relevant variables, agents, and impacts. It would be necessary to assign initial values and to specify rules of interaction among the agents. How would we even begin? Fortunately, the scientific and engineering literature provides good starting points with respect to interactions between any two agents. For our example of volcanic ash, the article “Volcanic ash impacts on critical infrastructure” by Thomas M. Wilson and colleagues is especially helpful.23 My illustration here focusses on a subset of those hazards.

Shown here is a portion of a possible agent- Ashfall topography is an emergent phenomenon based model for an eruption of Mt. Fuji. Bear in that derives from the interaction of a cluster of mind that the processes illustrated here would variables. Consider next the first round of play out over time, and the model would impacts in the center, only a few of which are produce different results for different time listed here. Most of Japan’s rivers are dammed, intervals. Let us begin with the blue boxes to and ashfall might affect dams in various ways the left. They indicate the major variables that (e.g., altering water flow, water levels, constitute the quantity, quality, andinterfering with the physical operation of distribution of ash. Wind speed and direction, dams), some of which might lead to flooding or other conditions, the quantity of ash adversely affect the power grid. Similarly, large erupted, the length of time of the eruption, quantities of volcanic ash often forms rock-like distance from the cone, and other variables clogs in ware runoff and drain systems, (e.g., height of the ejected ash) create what I thus resulting in flooding. Parts of the electric call an “ashfall topography.” Initial values for power grid are susceptible to ash damage, and these variables might be those of the 1707 power outages, or a complete shutdown, might eruption, insofar as they are known,exacerbate flooding, cause other infrastructure supplemented with data from other eruptions problems such as shutting down fueling of similar volcanoes elsewhere. Consider the systems, and directly interfering with “Other weather” variable briefly. Volcanic ash emergency response. Ashfall itself contributes has a different effect on components of the to physical obstruction of roadways, bridges, electric power grid depending on whether it is and airspace. Flooding, too, would likely dry or damp. A light rain, for example, might contribute to land obstructions and alter the create a paste that causes a phenomenon ash topography (and vice versa). Volcanic ash known as flashover (see the Wilson article for damages auto and aircraft engines. All of these details), but a heavy rain might wash ash out of impacts would adversely affect emergency places where it might otherwise causeresponses such as firefighting or the

13 13 | 33 | 6 APJ | JF distribution of essential food and medicine. fatalities. In some cases (e.g., wind direction), Other impacts might include a deterioration of these agents may be entirely beyond human sanitary conditions, leading to the spread of control, but in some cases it may be possible to disease, strains on medical infrastructure, and alter the conditions. In any case, such more. knowledge would be valuable.

Not fully shown in the diagram are the What about the short term? One insight from feedback loops and interactions between these complex systems theory is a tradeoff between various agents whereby both adapt to each exploration and exploitation. Because optimal other, thus altering the system as a whole, points in complex systems are rarely clear and which in terns cases more of its agents to rarely stable, additional exploration (more data adapt. On other words, the complex system collection, creating better models, running would not play out in a linear, additive manner, more simulations, etc.), if well done, is likely to but in a way such that the whole would be more produce useful knowledge. The opportunity than the sum of its parts and would change cost for such exploration, however, is fewer over time. resources devoted to exploiting whatever knowledge we currently have. Major volcanic It should be clear from this brief illustration eruptions are rare events compared with that creating a robust, sophisticated model for natural hazards such as typhoons, flooding, or an eruption of Mt. Fuji or other natural hazards even earthquakes. Our big picture knowledge would require carefully coordinated teams of of the way volcanic hazards are likely to play experts. Most likely, the model would need to out in the complex system that is Japanese be created in modules. After completion, such a society tends to be narrowly focused. model would need frequent tuning. After the Nevertheless, there is little choice but to model is reasonably well tuned, exploiting it, devote some resources to exploiting that that is running simulations with under different meager knowledge—that is, to allocate sets of conditions, would likely take years. resources and devise plans to mitigate likely Serious resources and work on such a project volcanic hazards based on best estimates might require a decade or more produce without the aid of powerful models. The something useful. Such a model would not be historical record, too, if used with caution, can able to predict the onset of volcanic eruptions inform this exploitation process. My larger or earthquakes, in part because the basic point, however, is to argue for—or at least physical mechanisms for the causes of these suggest the possibility of—the need for more phenomena (especially earthquakes) are not and better exploration (modeling) to set the yet known with sufficient precision to create stage for effective mitigation of volcanic and viable rules for agents. The promise of agent- other natural hazards in the future. based models would be the ability better to understand the interaction of volcanic or other Volcanic hazards are clearly a danger to many hazards with society and to identify especially parts of Japan and elsewhere. The existence of important variables or agents. Could such a nuclear power plants exacerbates the risks for model tell us how many people would likely die Japan and the region. Indeed, more so than in an eruption of Mt. Fuji? Possibly. Perhaps seismic hazards, volcanic hazards have the more important than estimating an absolute potential, in the most extreme cases, to disrupt number of fatalities, a well-designed model the ecosystem of the entire earth. It makes would likely identify currently unsuspected sense, therefore, to take obvious short-term agents or conditions that would contribute to a steps to prepare for likely volcanic hazards. relatively higher or lower incidence ofAlthough these points should be obvious, the

14 13 | 33 | 6 APJ | JF devil is in the details with respect to resource Perspectives on Conundrums of Technological allocation and social priorities. Moreover, the Modernization, Amelioration and complexity of contemporary society contributes Disasters in Modern Japan to a lack of knowledge about what will actually happen in the case of a major eruption. My • Shineha Ryuma and Tanaka Mikihito, Mind proposal here for a sustained effort at more the Gap: 3.11 and the Information Vulnerable sophisticated modeling offers no panacea, but it is one suggestion for dealing more effectively • Yasuhito ABE, Safecast or the Production of with this problem in the future. Collective Intelligence on Radiation Risks after 3.11 Gregory Smits is an Associate Professor of History at Pennsylvania State University. He is • Gregory Smits, Danger in the Lowground: a social and cultural historian of Japan, whose Historical Context for the March 11, 2011 interests range from the fifteenth through the Tōhoku Earthquake and Tsunami early twentieth centuries. A specialist in the history of the Ryukyu Kingdom and of the • Peter Navarro, Earthquake Repercussions impact of earthquakes on society, he is the Spur Rethinking of China's Dam Building author of Visions of Ryukyu: Identity and Strategy Ideology in Early-Modern Thought and Notes Politicsand co-editor with Bettina Gramlich-Oka of Economic Thought in Early-Modern 1 “Greater volcanic activity in Japan looks like Japan. He is the author of two studies of the new norm,” The Asahi Shinbun, May 30, Japanese earthquakes: When the Earth Roars: 2015. Lessons From the History of Earthquakes in Japan and Seismic Japan: The Long History and 2 For a typical example of how Kimura’s claims Continuing Legacy of the Ansei Era have been reported in the popular media, see Earthquakes. “’Mt. Fuji Should Erupt by 2015’: Ryukyu University Professor Emeritus,” Rocket News Recommended citation:Gregory Smits, 24, January 8, 2013. "Volcanic Hazards as Components of Complex Systems: The Case of Japan", The Asia-Pacific 3 Brenguier, F. Campillo, M., Takeda, T., Aoki, Journal, Vol. 13, Issue 32, No. 6, August 17, Y., Shapiro, N.M., Briand, X., Emoto, K., & 2015. Miyake, H., “Mapping pressurized volcanic Related articles fluids from induced crustal seismic velocity drops,” Science¸ Volume 345, Issue 6192 (July •Kyle Cleveland, Mobilizing Nuclear Bias: The 4, 2014): 80-82. DOI: 10.1126/science.1254073. Fukushima Nuclear Crisis and the Politics of 4 Uncertainty See here (accessed 7-13-2015).

5 •Oguma Eiji, Nobody Dies in a Ghost Town: See “A Second Look at Nuclear Power,” in Path Dependence in Japan's 3.11 Disaster and Issues in Science and Technology (Spring Reconstruction 2005).

6 • David McNeill and Paul Jobin, Japan’s Triple See, for example, Nassrine Azimi, “Japan’s Disaster, Introduction Natural Perils, and Promises, in the Wake of Fukushima,” The Asia-Pacific Journal, Vol. 12, • Philip C. Brown, Call it A ’Wash’? Historical Issue 43, No. 1, October 27, 2014, especially

15 13 | 33 | 6 APJ | JF the first several paragraphs. For a specific shinbun, November 19, 1915, morning edition, linking of Mt. Fuji and the plant at Hamaoka, 5. see Akio Matsumura, “Japan’s Fault: The Risks 15 of Mt. Fuji’s Eruption and Nuclear Power.” July Report quoted in Musha Kinkichi,Jishin 31, 2013. namazu (Akashi shoten, 1995), 76-77.

16 7 The original reporting includes “Genpatsu: Shimamura Hideki. Nihonjin ga shiritai jishin Kazangakusha ‘kyodai funka, risuku’no gimon rokujūroku: jishin ga ōi Nihon dakara Hokkaidō・Tomari nado eikyōdai—Mainichi koso chishiki no sonae mo wasurezu ni (Soft shinbun ankeeto,” Mainichi Shinbun, December Bank Creative, 2008), 90-92. 23, 2013, Tokyo edition and “Kurōzuappu 2013: 17 Kyodai funka, genpatsu no rinku hassei hindo David Rothery, Volcanoes, earthquakes, and hikuku, yosoku konnan okoseba ‘higai jindai,’ tsunamis (McGraw-Hill, 2007), 60. Mainichi Shinbun, Decenber 23, 2013, Tokyo 18 “Volcano Hazards including edition. Lahars,” (accessed 7-17-2015). 8 To cite but one of the many examples, see 19 For example, in addition to some of the items “Japanese volcanologists say several nuclear cited previously, see David Wolman, “Mt. Fuji power plants at risk if major eruptions Overdue for an Eruption, Experts Warn,” happen,” Japan Daily Press, December 24, National Geographic News, July 17, 2006; 2013. Martin Frid, “What Will You Do If Mt Fuji 9 C. B Connor, R. S. J. Sparks, M. Díez, A. C. M. Erupts?" Treehugger, December 15, 2008; F. Volentik and S. C. P. Pearson, “The Nature of Brenguier, et. al., “Mapping pressurized Volcanism,” in Charles. B. Connor, Neil A. volcanic fluids from induced crustal seismic Chapman, and Laura J. Connor, eds., Volcanic velocity drops,” Science, Vol. 345, Issue 6192 and Tectonic Hazard Assessment for Nuclear (July 4, 2014), 80; Lily Kuo,“What would happen if Mount Fuji erupted for the first time Facilities (Cambridge University Press, 2009), in 307 years?” in Quartz, July 17, 2014; Sara 94-95. Gates, “Mount Fuji Is In A 'Critical State' And 10 Connor, et al., “The Nature of Volcanism,” Could Be Ready To Blow, Researchers Say,” 97. The Huffington Post, July 17 [updated July 24], 2014; “New evacuation plan for Mount Fuji 11 For example, see Kazue Suzuki, “Japan’s Plan eruption calls for 1.2 million to flee,” Japan to Restart Nuke Plants Ignores LessonsTimes, February 6, 2014. Learned From Fukushima,” in Ecowatch, July 20 16, 2014. Major earthquakes usually happen without any warning. The earth suddenly shakes. Even 12 The KamLAND Collaboration, “Partialin cases where there are foreshocks in the radiogenic heat model for Earth revealed by weeks, days, or hours before a main shock, geoneutrino measurements,”Nature there is no way to know at the time whether a Geoscience 4, 647–651 (July, 2011),relatively small earthquake is the main shock of doi:10.1038/ngeo1205. its own event, an aftershock of some past event, or a foreshock of a future event. By 13 UCL Volcano Co2 Group,“Sakurajima” contrast, a well-known set of changes usually, accessed 715-2015). but not always, takes place over the course of days, weeks, or (often) months prior to the 14 “Tsūzoku jishin monogatari” (jō),Yomiuri occurrence of a large eruption. Traditional

16 13 | 33 | 6 APJ | JF monitoring methods include strategically mathematics of averages. With a given total of positioned seismometers, measurements of national resources that can be brought to bear, ground deformation, and the monitoring the what tactics and strategy will most promptly quantity and qualities of certain volatiles. win a war, or, better: what sacrifices of present Increases in the frequency of smallselfish interest will most effectively contribute earthquakes around the magma chamber(s), to a stable, decent, and peaceful world?” increased ground swelling, and increased Warren Weaver, “Science and Complexity,” quantity of gas emitted (as well as changes in American Scientist, 36: 536-544, 1948. (reprint the qualities of the gas) are all classic signs edition, p. 5). that magma is expanding. Typically, this expansion plays out over enough time for 22 For many examples, some specific to Japan, people nearby to evacuate safely. see Charles. B. Connor, Neil A. Chapman, and Laura J. Connor, eds., Volcanic and Tectonic 21 Several of the many examples of middle Hazard Assessment for Nuclear Facilities region problems Warren proposed are: “How (Cambridge University Press, 2009). can one explain the behavior pattern of an organized group of persons such as a labor 23 Wilson, T.M., et al. “Volcanic ash impacts on union, or a group of manufacturers, or a racial critical infrastructure.” J. Phys. Chem. Earth minority? There are clearly many factors (2011), doi: involved here, but it is equally obvious that here also something more is needed than the 10.1016/j.pce.2011.06.006.

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