Mount Etna, Sicily: Landscape Evolution and Hazard Responses in the Pre-industrial Era

Abstract

Mount Etna dominates eastern Sicily, being over 3000 m in height and covering an area of some 1750 km². Etna has instilled a sense of awe in men and women for thousands of years (Fig. 15.1); to voyagers in the Classical Age it was considered the highest point on Earth (King 1973a) and, even before the colonization of the island by the Greeks ca. 740 BC, members of Sicel culture were practicing cults that associated volcanism with subterranean processes (Chester et al. 2000).

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Mount Etna dominates eastern Sicily, being over 3000 m in height and covering an area of some 1750 km². Etna has instilled a sense of awe in men and women for thousands of years (Fig. 15.1); to voyagers in the Classical Age it was considered the highest point on Earth (King 1973a) and, even before the colonization of the island by the Greeks ca. 740 BC, members of Sicel culture were practicing cults that associated volcanism with subterranean processes (Chester et al. 2000).

Fig. 15.1

Mount Etna region and Sicily: general location map. (From Chester et al. 1985)

Volcanologically Etna is not only large, but also one of the few continental volcanoes that is continually active. Etna’s volcanic activity was initiated about 300–400 ka BP in what was then a marine gulf on the east coast of Sicily (Bonaccorso et al. 2004). Etna’s last catastrophic eruption occurred around 15,000 years ago, led to caldera collapse and the eruption of hot and potentially highly destructive pyroclastic flows, which swept down the southwestern flank of the volcano (Guest et al. 2003). Since then Etna has been characterized by basaltic activity, with the principal hazard being posed by lava flows. The vast majority of lava flows on Etna show aa morphology with a rough surface made up of irregular lava fragments. The name ‘aa’ is derived from the onomatopoeic Hawaiian word a’ā, which means hard to walk on, but a small proportion of flows show ‘pahoehoe’ morphology, again an Hawaiian word and typically describing a flow with smooth, lobate and undulating surfaces. There have been very infrequent explosive eruptions, which are unusual on a basaltic volcano, and these have deposited a few centimeters of tephra (volcanic ash) beyond the margin of the volcano. One example of such an event was the eruption of 122 BC when tephra fall brought about extensive damage to Catania during the Roman era and, more recently, tephra from the 2001 eruption caused considerable disruption to communications.

In terms of the relationships between people, land, and the creation of distinctive landscapes, Etna is fascinating because, in spite of the ever present threat of volcanic eruptions and earthquakes, since ancient times the region has attracted settlers in large numbers. Catania, the principal city of the Sicilian east coast, has been badly affected by both these phenomena, and during the past 2000 years has been destroyed in part by earthquakes in 1169 and 1693, and by lava flows in 1669 and probably also in 1371 or 1381, the dating being uncertain (Chester et al. 1985, 2005). This paradox between the hazardous character of the environment and the region’s attractiveness for settlement may be accounted for by a number of physical and human factors which operate at two distinct scales. Etna occupies an east coast location within Sicily (Fig. 15.1) and at an all-island scale part of the reason for its development is related to deep-seated and long-recognized contrasts between the coastlands and the interior, which Italian geographers commonly refer to as the “ugly picture in a frame of gold: the dry poverty-stricken core of the island contrasting vividly with the intensively-cultivated, irrigated coastal periphery” (Fig. 15.2; Milone 1960; King 1973a, p. 112). At the more detailed scale Etna has developed in a distinctive way, not just because people have had to respond to hazards, but also through a combination of factors that include not only particularities and variations in climate, vegetation and soils, but also distinctions caused by history, economy and culture. This makes the Etna region in some respects similar to, yet distinct from, other portions of the “frame of gold” (King 1973a, p. 112) and its unique character has made it of interest not just to volcanologists and other earth scientists, but also to classicists, historians and prehistorians, geographers and rural-sociologists (Leighton 1996, 1999; Chester et al. 2000; Malone and Stoddart 2000; Duncan et al. 2005; Smolenaars 2005).

Fig. 15.2

The contrast between the intensive and extensive agricultural areas in Sicily. It should be noted that the Plain of Catania only became an area of intensive cultivation late in pre-industrial times. In the 1940s this area had a low population and little commercial agriculture due to its malaria character. From the 1950s new irrigation techniques were introduced and malarial was eradicated. (From King 1971)

Although important social and cultural particularities remain, today Sicily is closely integrated into the economies of Italy and the wider European Union, but even as late as the late 1960s and early 1970s major elements of the pre-industrial society still persisted and reflected an interplay of people and environment that had produced distinctive agricultural landscapes and which had developed over hundreds, in some cases thousands, of years of settlement. For instance, the 1971 census recorded a Sicilian population of around 5 million, of which the percentage employed in agriculture varied from 20% to 40% depending on province, with an estimated 50% of the island population still dependent on agriculture to some degree (King 1971). Administratively most of the land area of Etna is contained within the Province of Catania and, reflecting its “frame of gold” location and other more localized features of attraction, accounted for 20% of the population of Sicily and some of the highest population densities found on the island. In 1971 figures of up to 800 persons/km² occurred in local authority areas (‘comuni’) located close to Catania, whilst elsewhere densities of 500 persons/km² were far from uncommon, densities declining with both increasing height on the volcano and with increasing distance from Catania. In contrast, for the island as a whole, an average population density in 1971 was 181 persons/km².

1 The Ugly Picture in the “Frame of Gold”

The reasons for the contrasts between central Sicily and its coastal margins, including Etna (Fig. 15.2), are due to both environmental differences and contrasting historical, social, and economic circumstances. With regard to environmental factors these include: higher annual rainfall on the north coast (up to 800 mm) and on Etna (700 mm to over 1250 mm), in comparison with totals of only 700 mm and usually far less in the interior (Fig. 15.1); the fact that flat land is rare in Sicily, plains only accounting for just 7% of the land area and with a strong concentration near to the coast; and the greater soil and irrigation potential of the island peripheral margins (Pecora 1968; Chester et al. 1985).

There is a lack of certainty about when humans first became established in Sicily, though stone implements on the plain of Catania and in the Province of Agrigento (Fig. 15.2) point to Lower Paleolithic times, but the evidence is ambiguous. By the Upper Paleolithic (ca. 18,000 ¹⁴C year BP; Table 15.1) human presence is more certain and Sicily was widely inhabited (Leighton 1999), though recent palynological studies based on evidence from lacustrine sediments from the Lago di Pergusa in Central Sicily (Fig. 15.2) suggest that the first major impact of people on the vegetation of the island occurred much later, by 2800 ¹⁴C year BP if not slightly earlier (Sadori and Narcisi 2001; Sadori et al. 2008). This date coincides with the early Bronze Age, a time of population growth in the lowlands and some expansion into the uplands including Etna (Table 15.1; Malone and Stoddart 2000). Indeed Leighton comments, “Etna, Europe’s largest volcano, (is) characterized by an extraordinary ecosystem. Here one may detect human adaptations peculiar to the environment of its lower slopes: well-watered fertile, with a rich and varied fauna and flora, and numerous caves. If it were better documented the archaeology of Etna would constitute a remarkable case study in European prehistory” (Leighton 1999, p. 4). Lava-flow caves provide convenient sites for habitation and several on Etna have yielded Copper Age material. Lava-flow caves are lava tubes and these develop on lava flows when an active feeding channel roofs over. When lava supply ceases the active lava drains and produces a lava tube (Table 15.1).

Table 15.1 Sicily: Phases and dating of prehistoric and historical development. (Based on information in Finley 1968; King 1973a; Leighton 1996, 1999; Malone and Stoddart 2000; Ayala and French 2003, 2005). The locations of places mentioned in the Table are shown on Fig. 15.1

The contrasts between the center and the coastal periphery are largely the result of both farming techniques and social and economic systems introduced by later invaders, particularly the Arab (827–1091) and later Norman, Spanish, and Bourbon rulers (Table 15.1), who in combination produced forms of land use and a social system that remained virtually unchanged for centuries. Small-scale irrigation was introduced by the Romans, but it was only after the Arab conquest from the ninth century AD that these techniques became widespread. Diffusion of irrigation depended chiefly on the ready availability of ground water and here the northern coastal margin and the Etna region were particularly favored, with crops such as bananas, bitter oranges, lemons, melons, mulberries, possibly cotton, sugar cane, the date palm, and pistachio nuts being introduced. Sumac was brought into the island for tanning, hemp for caulking, and livestock rearing was intensified (Mack-Smith 1968; Benjamin 2006). By the Early Middle Ages most of crops found in Sicily today were being cultivated, though maize, the prickly pear cactus, the potato, tomatoes, and tobacco were only introduced from the New World after the close of the fifteenth century (King 1973a).

Decline in the fortunes of the interior lands may be placed firmly at the door of Arab and later rulers. The Arabs cleared vast tracts of land for settlement, later timber was exported and/or used for shipbuilding and large areas of the interior were given over to extensive grazing, an unsuitable land-use for the easily eroded soils of the rolling hills found in the interior. Grazing animals provided hides, wool, meat, and cheese for export. In studies of soils in southern Italy, a distinction is often drawn between those found on Pliocene and other clay outcrops and those which occur on other substrates (King 1973b). The former are characteristic of vast areas of central Sicily, where the clays are described as scagliose, or scaly. Here soils are baked during the long summer drought, but become water saturated, viscous, and impermeable in winter. Shallow ploughing in spring and autumn using traditional techniques of peasant farming, has progressively caused the upper levels of soil profiles to become unstable and rendered them highly susceptible to erosion. The soil map of Sicily (Fierotti et al. 1988) records erosion in 24 of the mapped 33 soil associations found on the island, while the CORINE organization (European Environment Agency’s Co-ordination of Information on the Environment) also highlights a high risk of soil erosion (CORINE 1994). The worst-case scenario, which assumes no vegetation cover, shows not only high potential rates for the western half to two-thirds of Sicily including the interior, but also for Etna and the highlands of the north east. Actual soil-erosion risk under current land-use and vegetation cover is, in contrast, reduced for the whole island, remains significant for the center and west, particularly for the interior lands, but is greatly reduced for Etna and much of the north east (CORINE 1994). Late in pre-industrial times in the 1920s and 1930s the situation was further exacerbated and the campaign by the fascist government of Mussolini to achieve national self-sufficiency in grains, saw many of the more marginal interior lands being brought under intensive wheat cultivation using fertilizers. The land could not long withstand being sown with wheat year after year, though whether this was due to erosion or because of a decline in fertility is not made clear (Grove and Rackham 2001).

Socially as well as economically, core and periphery were very different, the latter having greater prosperity, being more cosmopolitan and with a more innovative population than was to be found in the interior. Latifundia estates were established in central Sicily by the Romans (Table 15.1), but their diffusion over the interior lands was largely the result of later rule, gifts of estates under a system of patronage often being granted as rewards to nobles who had rendered service to the ruler (King 1973a, b). Estates were almost invariably subdivided and under the management of agents (‘gabelloti’, in Italian) who controlled the renting of small plots to peasant farmers. Landowners (‘baroni’, in Italian) were usually absentee and the gabelloti had untrammeled power to raise rents against a background of severe population pressure that produced widespread land hunger. In order to survive, farmers had to maximize their incomes by adopting a virtual wheat monoculture, by over-cropping without rotation or fallow and by cultivating steep slopes. Widespread lawlessness made the situation worse. The gabelloti class was strongly associated with the mafia and, in addition, banditry and crime became part of the way of life and death throughout much of interior Sicily. In contrast eastern Sicily, including most of the Etna region, was relatively free of organized crime (Rochefort 1961). In the late nineteenth century especially after 1890, conditions did improve somewhat due to an opening of the safety valve of emigration especially to the USA (United States of America), but poverty remained endemic for many more decades. Demographic change introduced a further element of contrast with the coastal periphery, which did not lose population at anything like the same rate. The population of the Etna region in fact increased. This phase of migration peaked in 1913 at a figure of over 148,000 persons/annum and thereafter fell rapidly especially following the introduction of immigration controls by the USA in the 1920s (Benjamin 2006). The 30 years from 1947 saw a new phase of emigration which involved young skilled workers, rather than landless peasants. Emigration was primarily to northern Italy and other countries of Western Europe and this time the Etna region and the rest of the “frame of gold” were not immune from its effects. The impact in the interior was far more significant, however, and throughout all phases of migration the Province of Catania increased its share of the island population, due to a combination of natural increase and internal migration from other areas of Sicily. For instance, in 1861 the Province of Catania accounted for 15% of the population of Sicily, by 1901 this had risen to 16% and stood at 20% of the island’s total in 1971 (Chester et al. 1985).

In Sicily agricultural settlement was not diffuse and farmers usually lived in large agro-towns or peasant cities, commuting to their agricultural holdings on a daily and sometimes on a twice daily basis. Agro-towns had populations of between 3000 and 15,000 people or even more, and in pre-industrial times had at least 50%, sometimes 90%, of their inhabitants engaged in agriculture (King and Strachan 1978). A few settlements are known to have been continuously occupied since pre-Hellenic Sical times (Table 15.1), but many have no certain date of foundation. Alfred Demangeon (1927) has argued that agro-towns were funded as a result of several interlocking factors, which included natural conditions, plus ethnic and social linkages between the first settlers, but his principal insight was that these peasant cities continued to exist because of social and economic inertia, since they served to alienate and separate farmers from their land and so reduced agricultural efficiency—not least because of lengthy journeys to work.

In the coastal margin, agro-towns are also a feature of the landscape, though on Etna they are not found on hilltops so shortening journeys to work and reducing the negative effects on agricultural efficiency. In pre-industrial times the residents of these villages were more open to outside influences (Chester et al. 1985).

2 The Uniqueness of the Etna Region

In contrast with the interior of Sicily, during pre-industrial times the Etna region was marked by greater affluence, which was based on more productive agriculture. Etna not only showed a unity in terms of its relative prosperity, but also contrasted with the interior in other respects. Despite often continuous cropping of some areas for over two thousand years, production on Etna was sustained without either reduction in yield or significant soil erosion, and this is further discussed in Sect. 15.2.1. At a more detailed scale and within the overall unity of relative wealth and sustainability, there was a diversity in the distribution of land uses on the volcano, which demonstrated a fine adjustment to both: the physical environment and the economic potential of different sectors and height bands on the volcano, and the ever present danger of earthquakes and volcanic eruptions, particularly the threat of lava inundation. The proportion of the surface area of Etna covered by lava since 1600 AD is significant (Fig. 15.3; Table 15.2) and includes flow fields that have extended to the margin of the volcano. The hazard can be assessed and, as demonstrated by Guest and Murray (1979), many of the towns and villages on the flanks of the volcano are located in low hazard zones, through a process of natural adaption which is further discussed in Sect. 15.2.2. Although lava flows have caused considerable damage to agriculture, communications and occasionally settlements, on Etna they do not pose a significant risk to human life.

Fig. 15.3

Geological map of Mont Etna. (From Guest et al. 2003)

Table 15.2 Details of principal crops and agricultural activities during the pre-industrial era. (Based on information in Basile 1941; Chester et al. 1985; Dazzi 2007)

2.1 Adjustments to Environmental and Economic Factors

The agricultural landscapes of Etna have fascinated scholars for many centuries and the following account is based largely on the works of these writers, plus field observations and other referenced sources where appropriate (Rodwell 1878; Basile 1941; Milone 1960; Rochefort 1961; Pecora 1968; Clapperton 1972; King 1973a; Duncan et al. 1981; Chester et al. 1985; Dazzi 2007).

A full discussion of climate and hydrology of Etna is beyond the scope of this chapter (Chester et al. 1985), but its essential features are: an increase in precipitation with height, to over 1200 mm in the summit zone; a steep environmental lapse rate of temperature, so that heavy snowfall is a feature of winter months; a temperature contrast between the warmer northern, north-western, western and other sectors of the volcano; the occurrence of a volcanic plume driven by the prevailing westerly winds, with a concomitant rainfall enhancement and slight temperature depression on the eastern and south-eastern sectors of the volcano, in comparison with the more arid northern and north-western flanks; and high irrigation potential. With regards to the latter, aquifers are recharged by winter rainfall and snow melt, and since Roman times have been exploited for irrigation (Table 15.1).

On a volcano with such strong altitudinal and sectoral variations in climate, it is hardly surprising that at first sight the link between climate/hydrology and land use appears to be a deterministic one, with much more intensive cultivation, usually under irrigation, occurring in the eastern, south-eastern, southern and south-western sectors, within the so-called ‘regione piedmontese’ (mountain foot (piedmont) region), which stretches from sea level to 1000 m (Fig. 15.4; Table 15.2). In reality the relationship was more complex because the northern and north-western sectors of the volcano were isolated from Catania, the major city and market center of the region, and from the principal export ports of the east coast (Fig. 15.1). Land-use intensity declined with increasing distance along all principal routes linking Catania to other parts of the Etna region. Variations in land-use intensity were striking and, based on the land below 2000 m and the percentages utilized for the cultivation of vines, orchards and other plantation crops, in the final years of the pre-industrial era intensity varied from 3% in the northwest, through 23%, 27% and 41%, respectively, on the western, northern and north-eastern flanks, to 52% in the south; 63% in the east, 67% in the southwest and 69% in the southeast (Chester et al. 1985).

Fig. 15.4

View of the Etna from Catania in the 1870s. The contrast between the intensively cultivated regione piedmontese and the barren upper slopes of Etna should be noted. (From Rodwell 1878)

The principal pre-industrial land uses of Etna are summarized in Fig. 15.4, 15.5, Table 15.2, but there are a number of additional points that are not fully captured by these illustrations. For instance, yields were maintained in areas of intensive cultivation by a combination of (a) inter-cropping of cereals and vegetables, usually sown beneath tree crops; (b) the creation and maintenance of elaborate lava-block terraces on steep slopes, that were well established in Sicily by the thirteenth century and which created flat land and also acted as an effective means of erosion control; (c) wood-mulch was widely used both to increase organic matter and reduce evaporation; (d) great care was taken over grafting, so as to maximize yields and reduce labor requirements; and (e) animals were closely integrated into the system of cropping. Animals not only produced meat and other products for both on-farm and local consumption, but also provided a vital source of manure.

Fig. 15.5

The agricultural land-use of Etna. (After Rochefort 1961)

Cultivars were carefully chosen for the particular conditions encountered on Etna and some, including the Nerello Mascalese and Carricante grapes, were used for many centuries, although additional varieties were introduced late in the pre-industrial era (Dazzi 2007).

Maintaining this system of agriculture demanded large drafts of family and extended family labor and by the close of pre-industrial times in the 1970s terraces abandoned from cultivation, but still in use for grazing, were a feature of the landscape. These bore witness to a reduction in the area being intensively worked especially towards the upper altitudinal limit of the regione piedmontese. This was due to a combination of: investment by the Italian State and the European Economic Communities in larger units, mechanization and more modern techniques of irrigation—so producing scale economies and spatial concentration; and to a reduction in the agricultural labor force, particularly sons and daughters of farmers who were increasingly unprepared to be employed tilling family-owned plots (King 1971; Chester et al. 1985).

2.2 Adjustments to Hazards

The terms pre-industrial and industrial are not only used to portray societies at different levels of economic development, but also to describe responses to disasters caused by extreme natural events (White 1973). The nature of these two characteristic forms of response are summarized in Table 15.3, and for most of historical time societies throughout the world have had to respond “pre-industrially” when having to cope with disasters. Many inhabitants of economically less developed countries continue to do so even in the early years of the twenty-first century. In pre-industrial societies losses are accepted on an involuntary basis by individuals, families and isolated regions, but as the process of economic development takes place the burden shifts to the State and in large catastrophes to the international community, involving loss-sharing by means of aid transfers, insurance and the State assuming a central role, both as an aid provider, and as an agency seeking to reduce the impact of subsequent events (White 1973). This is known as an industrial or modern technological response. In Sicily there were few industrial features of responses evident until a hundred years ago, when in 1909 the State played a leading role in providing aid following the Messina earthquake. In the twentieth and twenty-first centuries major eruptions of Etna have occurred in 1910, 1911, 1923, 1928, 1950–1951, 1971, 1979, 1981, 1983, 1991–1993, 2001 and 2002–2003 and, albeit with some exceptions, this sequence has coincided with a progressively greater State involvement in managing the impact of volcano-related losses. Although from the Classical era until ca. 1900 there are a few historical examples of State involvement during and following eruptions of Etna (Chester et al. 2005), the best recorded examples were after 122 BC when inhabitants of Catania were granted a ten year tax moratorium by the Roman authorities (Rodwell 1878), and in 1669 AD when the Spanish Viceroy deployed troops and sent monetary aid to the region (Mack-Smith 1968). The dominant coping strategy until 1900 was typically pre-industrial, it included the features listed in Table 15.3 and reflected a fine adjustment of people to the Etnean environment. Although it is reported that troops were deployed during eruptions in 1874, 1879, 1883, and 1892, this was principally for the maintenance of law and order. In 1883 troops played a limited role and were deployed to prevent the population seeking shelter in churches because of the risk of a major loss of life caused by volcanic earthquakes, whilst in 1892 soldiers distributed bread and the very limited financial aid provided by the Italian State.

Table 15.3 Responses to hazards in contrasting pre-industrial and industrial societies. (Based on White (1973) and Chester et al. (2005))

In addition to the altitudinally fluctuating frontier of cultivation produced by temporal changes in economic and demographic pressures (see Sect. 15.2.1), throughout history and prehistory the cultivated area has not only been reduced by lava invasions, but also increased by the re-colonization of lava flows and associated volcanoclastics (Figs. 15.3, 15.5). In the case of incursions the distress caused to the population has been documented by many writers (Rodwell 1878; Hyde 1916; Chester et al. 1985). Dealing with just those eruptions that have occurred since the fifteenth century, when the records became reasonably complete: the villages of Trecastagni and Pedara were destroyed in 1404; in 1537 Nicolosi was devastated; in 1646 several small villages on the north flank of the volcano were reported to have been obliterated; the 1669 eruption, the largest historical event, wiped out Belpasso, S. Pietro Clarenza, Mascalucia, Comporotondo, S. Giovanni de Gelermo, Misterbianco, fourteen smaller settlements, and most of Catania; and a number of small villages were razed in the vicinity of Macchia in 1689 (Fig. 15.1). In pre-industrial times, the outskirts of towns and villages often comprised a corona, a roughly circular rim of particularly productive agriculture, and losses within such areas were recorded following eruptions in: 1371 (possibly ~1160) and 1444, in Catania; 1536, in Randazzo; 1566, in Linguaglossa; 1595 (possibly 1062); 1607 (possibly 1610), in Adrano; 1651–53, in Bronte; 1792, in Zafferana; 1810, in Milo; 1832 and 1843, in Bronte; 1852/3, in Zafferana; 1879, in Passopisciaro (located between Randazzo and Linguaglossa); and 1883, in Nicolosi. It has been calculated that between 1500 and 1900, some 8% of the total land area of the regione piedmontese was sterilized by lava flows (Chester et al. 2005).

It is often assumed that people panic when disaster strikes, but research across a range of disasters throughout the world shows that this rarely occurs. It was certainly not the case on Etna during the pre-industrial era because, although fearfulness and apprehension are noted in some accounts, the vast majority of reports bear witness to the fact that people remained calm, normal day-to-day activities continued unabated, people still farmed their land and continued with their trades. A strong sense of solidarity is evident as family and community coped with and recovered from lava incursions in a variety of ways. On Etna, eruptions of lava affecting settlements and agricultural land often occurred several times a century, inhabitants were familiar with the risks they faced and were able to adapt to them. People whose homes were under threat frequently made use of family and extended family relationships, leaving their villages to live with relatives. For instance, in the 1883 eruption it is reported that some of the threatened population in the villages of Belpasso, Biancavilla, Borello, and Nicolosi were forced to live in makeshift accommodation, in tents or in the fields, but in fact most people merely left their homes on a temporary basis to live with their families in other villages. Almost everybody returned once the emergency ended because only the village of Nicolosi was badly affected. Spontaneous evacuations also occurred during eruptions in 1843 and 1886. Even the tent and field dwellers were not invariably the marginalized poor as many nineteenth century press accounts imply, because many farmers owned permanent shelters on family plots that were normally used for a daily siesta in the hot summer months or for storage of tools and fodder, but could be easily converted into temporary family accommodation. In 1892 relief committees are also known to have been formed in several villages.

A remarkable feature of loss-bearing on Etna was that, although cities, towns and villages could be badly affected and even destroyed, they normally recovered rapidly. Nicolosi was, for instance, destroyed by lava in 1537, but was a prosperous settlement when an earthquake again badly affected the settlement in 1633 and was probably fully re-built by the time of the 1669 eruption (Fig. 15.1; Chester et al. 1985). This was not an isolated example and more than thirty nine towns and villages suffered losses between 1400 and 1900, some on more than one occasion, yet an area was never abandoned a settlement being either rebuilt on the same site or as close as possible to it (Table 15.4; Chester et al. 2005). Close to the vent of a high-effusion rate eruption, lava may travel at velocities of several kilometers per hour, but typically by the time flows reach inhabited areas they advance more slowly, normally at no more than tens of meters per hour. Residents knew in advance if and when their village and home was about to be destroyed and there is good historical evidence that people salvaged all they could (Chester et al. 2005). Salvage included furniture and personal possessions, but newsreel films of the slightly later 1928 eruption show that the removal of tiles, windows and doors was a well established practice (Duncan et al. 1996; Chester et al. 1999).

Table 15.4 Urban responses to major flank eruptions 1400–1900. Ticks indicate that relocation or rebuilding on the same site featured in the response. The impact of eruptions on Catania are discussed in the text and locations are shown in Fig. 15.1 (After Chester et al. 2005). The dates of historic lavas are from Tanguy et al. (2007)

Despite being devastated so many times by earthquakes and eruptions the city of Catania was never fully destroyed. It always remained functional both as a city and port, was still the focus of inland transport and, even in its ruined state, held far more locational advantages than any possible rival (Chester et al. 1985). Lava flows in contrast to earthquakes, sterilized the land over which they moved for hundreds of years and it could take several months before a flow had cooled sufficiently to allow site clearance to begin. Lavas from the 1669 eruption took over eight months to cool (Rodwell 1878). In the decades following each lava inundation, the urban area of Catania expanded over sterilized land, a policy of hazard adjustment that had the twin advantage that building sites were cheap and reconstruction did not have to compete with high-value agriculture. A similar expansion, but on a smaller scale, frequently occurred as villages spead over sterile land following episodes of lava inundation (Table 15.4).

All peasant agriculture involves maximizing family security over profit and one feature throughout Sicily is that cultivation plots are often owned in different localities. On Etna, parcels of land may be as small as 2 ha, but a family normally either rents or owns plots in several localities so that a single eruption is unlikely to wipe out all a farmer’s property (Clapperton 1972). Pastoralism also provided a means of increasing security and, although high altitude pastoralism has declined in recent decades, in pre-industrial times this was far more important and provided a valuable additional source of income especially in times of distress (Chester et al. 2005). High level pastures could be leased on a seasonal basis from large landowners, including the church, by members of an extended family.

Field work and the analysis of aerial photographs have shown that even on the relatively well-watered southern, eastern and south-eastern flanks of the volcano centuries may pass before cropping can recommence (Chester et al. 1985; James et al. 2000). When studied in the early 1990s, the 1928 lava flow, which destroyed the town of Mascali, only supported low-intensity rough grazing and in the few places where vegetation succession had not been influenced by humans, the lava was only covered with a ground flora comprising lichens, mosses, and some small trees where soil and moisture have been concentrated in depressions (Duncan et al. 1996). Left on their own lavas will be re-colonized by natural processes and soils will develop. It is not surprising that, given the complexity in the interplay between geology, relief and climate, and in terms of the mix of its soils and their spatial extent, Etna is striking as the most distinctive region of Sicily (Fierotti et al. 1988). Five soil associations are mapped for the volcano the pattern shows a broad relationship to elevation (Table 15.5). In terms of agricultural quality, apart from lava rock outcrop, the poorest soils of Mt Etna are Lithosols (Leptosols according to the WRB Classification; Deckers et al. 2002), young or eroded, shallow soils of minimal development in weathering lava. Eutric refers to the relative richness in basic elements, but the quality of Lithosols is limited by shallowness and the generally rugged terrain. Regosols are weakly developed soils in loose substrates, particularly tephra, but may be cultivated. Of greater pedogenetic development and agricultural value are the eutric Cambisols and Luvisols, well developed brown soils of good depth. On generally well drained and commonly glassy volcanic ashes and pyroclastics, Fierotti et al. (1988) describe these as having the distinctive andic properties of volcanic soils, namely low bulk density, high water retention and porosity, and relatively high organic matter and nutrient content. These soils are of greatest extent on the eastern, south-eastern, southern, and south-western lower flanks of the volcano.

Table 15.5 Soil associations mapped and described for Mt Etna by Fierotti et al. (1988). Soils in associations 5, 15 and 10 may have andic properties that confer low bulk density, high porosity, high water retention and good drainage. They are relatively rich in organic matter and nutrients

The broad distribution of soils on Etna is controlled primarily by climatic variation with sector and elevation, yet at many localities soil quality is related to the nature, depth, and age of soil-forming materials and varies spatially across distances as small as a few meters. Thus a local pattern of soils is likely to reflect age and morphology of lava, and the age and depth of tephra deposited across lava surfaces. Soil depth is critical in a region where it is highly variable and often limited. In agricultural terraces, soil depth is built up artificially. The authors find that terrace-soils, which were formerly cultivated but are now grazed, comprise tephra little altered by pedogenesis: the black tephra is coarse, loose and rich in little-altered volcanic glass (a soil property described as vitric), the only visible pedogenetic horizon being an organic-rich and shallow topsoil. The importance of soil depth in relation to other factors in soil fertility may apply to relatively young soils, but the soils of the oldest flows on the lower slopes of Mt Etna are markedly more developed, being finer-textured, brown Cambisols and sometimes Luvisols. These soils, associated with mature landscapes, are also terraced and carry a rich variety of more demanding crops. The patchwork of Etna’s geomorphology and soils, which occurs between very local and regional/sector scales, accounts in part for the great ecological and agricultural diversity of the volcano.

Tephra is the major constituent of many of Mt Etna’s soils, and its periodic deposition rejuvenates them. During the 2002–2003 eruption, 10 cm of tephra accumulated 5 km from the source. Citrus fruits and vegetables were badly affected and grapes had to be washed to remove ash; washing machinery could not be used because of damage by the abrasive ash, and oranges could not be processed economically for juice (Dazzi 2007).

Although in the absence of human interference lava will be re-colonized by natural processes, there is evidence that farmers both understood weathering and re-colonization and assisted it to a limited degree. By comparing geological maps and aerial photographs it is possible to see that farmers had an accurate perception of re-colonization potential. Etna generates relatively little pyroclastic ash, but where it occurs mature soils are produced far more quickly than on lava flows. Around the village of Nicolosi (Fig. 15.1), located on the south-eastern flank at a height of 700 m, vines have been established for a considerable time on Andosols developed from the pyroclastic ashes of the 1669 eruption, whereas adjacent lavas of the same age only support the low intensity grazing of livestock. King (1973a) also makes the point that farmers often encouraged natural weathering and processes of soil formation, with the prickly pear cactus (Opuntia ficus-indica) being introduced from South America so that the plant’s powerful roots could assist in the breakup of lava flows.

Although the perception that disasters are caused by supernatural forces in order to punish sinful humanity is not confined to pre-industrial societies and, indeed, transcends culture, time and religious tradition (Chester and Duncan 2010), generally in southern Italy and particularly on Etna (Chester et al. 2008) this attitude played a particularly prominent role in the ways in which people reacted to catastrophes caused by volcanic and tectonic processes. The tradition that Etna has a divine status is long-established and in fact may be traced back to before the period of Hellenic influence, with Maniscalco (2005) noting that the Sikel god, Hybla, was associated with a mud volcano at Paterno on the south-western flank of the volcano (Fig. 15.1). Later in the Classical Era the view emerged that the only course of action that people could take when threatened by the effects of an eruption was divine appeasement, with Lucilius Junior (first century AD) recording that the people offered incense to the gods who were thought to control the mountain and its eruptions (Hyde 1916). In the Christian tradition, theodicy is defined as any attempt to reconcile the notion of a loving God with the existence of human suffering, and southern Italian popular Catholicism modified the pre-Christian tradition to maintain that losses had to be accepted because they were a legitimate expression of a vengeful God’s punishment of a sinful people (Chester et al. 2008). All the inhabitants of Etna could do in response was to appeal to God in prayer and supplication, to try and propitiate wrath by liturgical actions and, in planning recovery from the disaster, resolve to live better lives. In the eighteenth century and strongly influenced by enlightenment thinking, alternative models of theodicy were given prominence especially by the philosopher Gottfreid Wilhelm Leibniz, but rural Sicilian Catholicism remained wedded to notions of punishment, with the only positive feature of a disaster—what theologians term the greater good—being found in the virtues of self-sacrifice, public service and social cohesion (Chester et al. 2005).

Given the manner in which the greater good was defined in Sicily, it is hardly surprising that from the earliest times heroic acts became the stuff of legend. Seneca, for instance, records the story of Anapias and Amphinomus—the so-called ‘Fratelli pii’ or pious brothers—who rescued their parents from a major conflagration in Catania, lava opening in front of them like the Biblical Red Sea and so allowing escape, whereas much later in 1669 Diego Pappalardo a local leader and some fellow citizens of Catania attempted to divert a flow which threatened their city, a course of action which caused a riot since the diverted lava now put Paterno at risk. Following this and for the rest of the pre-industrial era, attempted diversion of lava was made illegal (Chester et al. 2005).

A widely-held theodicy of punishment meant that eruptions became associated with liturgies of divine appeasement. Although intercession through the agency of the Madonna and the saints was an established part of mainstream catholic teaching, in the form of popular Catholicism practiced on Etna this was expressed in a distinctive and extreme manner, with saintly relics, statues and other votive objects supposedly having the ability to prevent disasters (Chester et al. 2008). As early as 252 AD when lava approached Catania, the inhabitants processed the veil of the recently martyred St. Agatha at the flow front which it was claimed was immediately halted. Following this early success the veil and objects associated with saints were used on numerous occasions: in 1669 it was asserted that Agatha’s veil prevented all Catania being destroyed; and as late as 1886 the veil was claimed to have been responsible for lava passing close to, but not destroying, the village of Nicolosi (Chester et al. 2005). The rural landscape of the Etna region was dotted with roadside shrines to saints and martyrs and an important part of the traditional way of life of each village was a festival (festa) dedicated to the local patron saint.

In pre-industrial times on Etna there was a marked psychological tension caused by an inconsistency between beliefs and actions. Sometimes called cognitive dissonance or parallel practice (Dibben 1999) the people of Etna, while on the one hand accepting that disasters were manifestations of divine wrath, on the other had no difficulties in reducing their risk exposure through, for example, exploiting extended family networks, having cultivation plots in different areas, and forming self-help committees. What is more from the eighteenth century some of the early geologists who studied Etna from a scientific perspective were priests, most notably the German Jesuit Athanasius Kircher and the Sicilian Canon Giuseppe Recupero who assisted the pioneer volcanologist Sir William Hamilton (Chester et al. 1985). This influence, however, did not displace or modify the indigenous popular Catholicism of the Etna region, with its emphasis on the supposed power of relics and votive objects and the efficacy of village patron saints and the Madonna to intercede for divine protection (Chester et al. 2008).

3 Conclusion: Landscape and Hazard Response Today

Although most characteristics of pre-industrial loss bearing on Etna have not been in evidence for a hundred years, some elements have survived (Table 15.3). Most notable are liturgies of divine appeasement which are still carried out each time there is a major eruption. Since 1970 major flank eruptions have affected or threatened settlement on the volcano in 1971, 1974, 1981, 1983, 1991–1993, 2001 (Guest et al. 2003) and in 2002–2003, and during most of these events religious rites have been performed, showing a continuity with the situation before 1900. These liturgical actions still enjoy overwhelming popular support and in July 2001, Luigi Bommarito Archbishop of Catania, celebrated mass in the village of Belpasso (Fig. 15.1; Chester et al. 2008), hopefully to halt the lava that was threatening the village. It is estimated that between 7000 and 10,000 people attended this open-air mass, representing a wide cross-section of the inhabitants of the village including many well-educated professional people. A teacher is quoted as remarking local people still believe in miracles. “If human technology can’t keep the lava back, the eternal father is our only salvation” (Kennedy 2001, p. 10). Furthermore, in detailed interviews carried out in the village of Trecastagni in the 1990s (Fig. 15.1), Dibben found that “for many (members of the public) religious beliefs play a significant role in their representation of the volcano” (Dibben 1999, p. 196). The parallel practice noted in pre-industrial times, of people accepting that disasters are manifestations of godly wrath which are only capable of being moderated through mechanisms of divine propitiation, yet at the same time fully embracing attempts to reduce risk and aid recovery through State supported actions, is still part of the psychological makeup of a large number of the inhabitants of Etna. Salvaging all that may be easily removed from a building before it is engulfed by lava has also remained an important means of coping. This well established tradition is probably not unrelated to the low take up of domestic property insurance which is both costly and of only limited availability (Chester et al. 1985). In spite of these exceptions, present day responses to periodic flank eruptions are industrial in character (Table 15.3), with emergencies being closely managed: by government, through the Ministry of Civil Protection (Dipartimento della Protezione Civile), and other scientific agencies, including the National Institute of Geophysics and Vulcanology (Istituto Nazionale di Geofisica e Vulcanologica INGV) in Catania; and by the use of technology and planning expertise, particularly hazard mapping, land-use zoning and geophysical monitoring. In this respect Etna differs little from volcanoes located in other parts of the economically more developed world (Chester et al. 2005) in terms of its hazard preparedness.

In introducing this chapter it was noted that many features of pre-industrial agriculture and the distinctive lifestyle of Sicilian agro-towns were still in evidence in the late 1960s and early 1970s. Over the past forty years poverty in Sicily has been reduced through aid and subsidies from the Italian State and the European Union, with the interior lands in particular benefiting from the programmes of land-reform which were introduced from the 1950s (King 1973a, 1973b). On Etna the regione piedmontese retains its agricultural distinctiveness and, though farmers now have access to machinery and subsidies, much of the traditional system of intensive irrigated agriculture described in Sect. 15.2.1 may still be recognized (Dazzi 2007). Since the 1970s, the policy towards concentrating investment in more environmentally favored and larger more easily worked and more accessible holdings within the regione piedmontese and on the plain of Catania has continued, and further abandonment from cultivation of more marginal land has taken place. The numbers employed in agriculture have fallen, those in service occupations have increased and many comuni, particularly those within easy driving distance of Catania, now serve as commuter settlements and contain many inhabitants who are far less aware of risks they face from the volcano than were their forebears four decades ago (Dibben 2008). The region is now a major tourist destination and since the early 1970s has attracted many second home owners. Especially in the settlements near Catania and adjacent to the coast, much of the traditional Sicilian way of life and the character of the agro-town has disappeared, though elements are still to be found in the more remote villages of the northern and north-western and western sectors of the volcano.