books and major references
the past 30 years a number of monographs, books, or collections of papers
dedicated to Etna have been published, about 100 years after the monumental
work by Sartorius von Waltershausen (1880) which, however, will be hardly
available to most readers. The following reviews are organized chronologically.
Full references are not given here, but they can be found easily on
the References page.
can be said that modern volcanology began to be applied at Etna during
its spectcular and destructive summit-flank eruption in 1971, which
resulted in a special issue of the Philosophical
Transactions of the Royal Society of London (volume 274A, 1973).
This contains numerous papers reporting the state-of-the-art of Etna
related studies and describing various aspects of the 1971 eruption.
Among the highlights is a paper by Guest which reviews the evolution
of the summit area up to the 1971 eruption. Much of the later publications
by this author and his collaborators (Duncan, Kilburn, Pinkerton, Chester,
Murray and others) build on this first synthetic analysis of the "normal"
eruptive behavior of the volcano in periods between flank eruptions.
the 1970s and early 1980s numerous studies were carried out by this
British working group at Etna. Preliminary results of this long-lasting
and multidisciplinary research were published in three volumes entitled
"UK research on Mt Etna",
which were published in 1974, 1977 and 1980. Generally these are hard
to find outside the UK - even in Catania, the Etna metropolis, only
few copies exist. However, much of the content of these volumes were
later condensed, in more elaborate form, in the geological map of Etna
(published in 1979 but onfortunately out of print long since) and in
a special issue of the Memorie della Società
Geologica Italiana (volume 23, 1982; edited by R. Romano)
which can be taken as extended explanatory notes to the geological map,
with additional information about seismological studies at the volcano.
Individual chapters deal with the geology of the Etnean basement, the
geological evolution and historical eruptions of the volcano, and styles
of its eruptive activity. Other chapters are devoted to the petrology
of the eruptive products and to the structural framework of Etna.
capable of reading German will have appreciated the publication of the
only field guide to Etna existing for a long time, the Führer
zu den italienischen Vulkangebieten: Ätna, by Pichler (1984).
That volume, while offering numerous itineraries to places of geological
and naturalistic interest on and around Etna, suffers from three major
problems. Firstly, it remains inaccessible to most of the international
audience for it is only available in German. Secondly, much of the information
on the geological framework, the evolution and dynamics of the volcano
and on the petrology of its products is based on obsolete concepts.
The third, and most serious, problem is that a field guide to a volcano
as active as Etna is rapidly out of date. While it was in print, Etna
produced its large and destructive 1983 eruption, which seriously affected
the main access route from south (Nicolosi-Rifugio Sapienza) and buried
some landmarks (such as the 1910 eruptive fissure) forever. The author
struggled hard to insert notes about the 1983 event in the book before
it was published, but in the year of its publication another significant
eruption occurred at the Southeast Crater, and since then Etna has erupted
many more times, producing large lava flows on its flanks, and the summit
area has changed beyond recognition. Today, the value of Pichler (1984)
lies rather in the fact that it represents some kind of a historical
"snapshot", both regarding the volcano, which is much different
now, and the concepts it embraces. On a more general level, the problem
with printed field guides for Etna is that they will inevitably become
obsolete very rapidly. The only solution to this problem would be a
virtual field guide available on the Internet, which would have the
enormous advantage that it can be updated as Etna continues to change
in the course of its eruptions.
marks the appearance of what is probably THE modern standard reference
work on Etna, "Mount Etna: The anatomy
of a volcano" by Chester, Duncan, Guest and Kilburn.
This book merits a lengthy discussion on its own, since it continues
to be the point of departure for anyone interested in learning about
Etna, and it will likely remain so for some time to come.
The authors, at the time of the publication of the book, were acquainted
with Etna since 10-15 years and had a profound understanding of the
dynamics and characteristics of the volcano during the period of their
studies. Much of what is said in "Mount Etna" is still valid
today, and it is presented in a well readable, enthusiastic and yet
"Mount Etna" consists of nine chapters and has an extensive
reference section plus an alphabetic name and subject index, the whole
filling 404 pages. The text is accompanied by 189 figures, many of which
are black and white photographs, which are generally well printed and
serve to complement the text well.
The first chapter entitled "The Forge of Vulcan" gives an
introductory account on the volcano and its activity, and presents an
outline of the difficult, though mainly fruitful, coexistence of Etna
and Man. It is followed by an account on the geographical characteristics
of the Etnean area, which appears to be largely the work of Chester.
The geological setting and evolution of Etna are presented in chapter
3, which also contains a detailed list of historical eruptive activity
through 1983. The fourth chapter deals with volcanic processes and products,
where the authors meticulously describe the various types of eruptive
activity, the resulting landforms, and eruptive products (pyroclastics,
reworked volcanics, and various types of lava flows). This chapter also
enlarges upon the peculiar behavior of the summit craters during the
years of study by Chester and his coauthors, which has changed to some
degree since then, as will be discussed below.
Much of the studies by the authors (especially Guest and Kilburn) were
devoted to the rheological properties of Etnean lavas - rheology is
the science of the way and rate at which rocks (and among them lavas)
deform and flow. The 5th chapter dives deeply into the Big Science (in
the sense of providing a lot of equations and graphic plots) when describing
the physical properties and flow behavior of lavas on Etna. This reflects
a surge of research concentrated on the phenomenon of lava flows which
was much en vogue in the early 1980s and has lived a recent revival.
Chapter 6 is an account on the petrology of Etna's rocks, with inferences
on the magmatic processes. In his review of "Mount Etna",
the late R.S. Thorpe (Journal of Volcanology and Geothermal Research
34, 1988: 318-319) remarked that this chapter was "uneven and less
comprehensive" than the other parts of the book (judged by him
as generally excellent), especially pinpointing the first section of
the chapter which deals with the isotope geochemistry of Etna's eruptive
products. Certainly petrological and geochemical studies of Etnean rocks
were much lass advanced at the time than they are now. Rather than being
assembled in the chapter on volcanic products (chapter 4), gas emissions
at Etna are discussed in the chapter of petrology.
The following chapter on Internal Plumbing is an interesting part of
the book, which relies heavily on geophysical studies, quite a young
science as applied on Etna. Seismic monitoring had been initiated less
than 20 years before the publication of the book, and ground deformation
and other geophysical studies even later, so that the data discussed
in this chapter are very preliminary; yet it provides a fascinating
glimpse into the internal structure of the volcano. It is in this sector
that research at Etna has made the greatest leap forward since "Mount
Etna" appeared in the bookstores, and the more important findings
will be compared to what is said in the book below.
Interestingly two chapters - #8 and #9 - deal with the problem of volcanic
hazards at Etna. Thorough reading of these chapters will lead to a better
understanding why there is this division, rather than presenting all
the content in one chapter.
Chapter 8 is a general treatment of the problem of volcanic hazards,
explaining what a volcanic hazard is, and which phenomena may be hazardous
at Etna. It furthermore deals with the predictability of hazardous events
and phenomena, and the likelihood that they will occur in a certain
location. To better constrain the magnitude of a certain hazard, the
vulnerability of the various sectors of the volcano is analyzed, together
with possible patterns in the eruptive behavior. The last bit of this
chapter forms a prelude to the next one - which is about the human response
and adjustment to volcanic hazards at Etna - in describing various techniques
applied to alter or stop the advance of lava flows.
The last chapter might also be entitled "Etna and Man", for
it describes many of the more or less unpleasant encounters between
both when the volcano erupted, and the way the inhabitants of the affected
areas reacted throughout history. Towards the end this chapter returns
to the theme already addressed at the end of the previous chapter, the
diversion of lava flows, which has remained a controversial issue to
the present day.
The effort put into this book is enormous, and I guess that any volcanologist
whose studies are concentrated on Etna, carries the secret wish one
day to be able to write what might be an up-to-date version of "Mount
Etna". But how would this book look like were it to be published
in the year 2003?
Certainly there would be more eruptions to describe, and with these
their effects on the population of the affected sectors and human response
to events like the 1989, 1991-1993, 2001 and 2002-2003 eruptions. Some
aspects of this issue have been discussed by the same authors (or some
of them) in more recent publications.
The structural setting of Etna has been studied extensively, and several
new hypotheses have been proposed which try to explain the vigorous
magmatism at Etna. Furthermore Etna is now considered by many scientists
to be but the latest manifestation of long-lived magmatism that resulted
in episodic volcanic activity in the Hyblean Plateau, to the south of
Etna, over hundreds of millions of years. These considerations would
occupy some space in the chapter on the geological setting of Etna,
along with the results of recent research on the tectonic structures
in the immediate Etna area (e.g., the "Timpe" fault systems
on the lower E flank of the volcano).
Equally, new findings on the geological evolution of Etna would have
to be included in the third chapter of the book. Among the most recent
revelations are the discovery of a debris avalanche deposit related
to (at least part of) the formation of the Valle del Bove, and a new
hypothesis regarding the eruption, emplacement and post-eruptive deformation
of the "pre-Etnean" volcanics at Acicastello, on the coast
of the Ionian Sea to the north of Catania. Abundant absolute and relative
age determinations have been made available for various stratigraphic
units and some individual deposits, allowing a much more detailed resolution
in time of Etna's history.
Although the authors picked up the concept of volcano instability (which
at the time was quite new, and essentially limited to catastrophic collapse,
stimulated by the catastrophic collapse and explosion of Mount St. Helens
on 18 May 1980) and applied it to the formation of the Valle del Bove,
they could not know how important this concept would become at Etna
during the following years. It is now fairly established that the eastern,
southeastern and southern flanks of Etna constitute a huge sector that
is affected by slow, generally non-seismic spreading and episodes of
more accelerated slippage accompanied by shallow seismicity. Although
the relationship of spreading and flank slip with Etna's magmatism has
yet to be constrained, flank instability appears to play a very significant
role in the on-going dynamics of the volcano.
The description of the behavior of the summit craters - and in particular
the Northeast Crater - would be decisively different from that provided
in the first and fourth chapters of the 1985 book. It is obvious that
in 1985 the authors described the craters as they knew them. However,
statements such as "eruptions from the Northeast Crater provide
the visitor to the summit with a spectacular display..." (page
7) are too generalized. The Northeast Crater had changed its behavior
years before the book was written, and the typical mild persistent activity
described in the cited passage has occurred at this crater only for
three brief periods in 1986, 1996, 1999, and once more in 2002, and
in general the activity at the Northeast Crater has declined to fairly
low levels in the past 15 years.
The statement that activity alternated between the Northeast Crater
and the two large craters in the former Central Crater (the Bocca Nuova
and the Voragine, called "the Chasm" in the book) but never
occurred simultaneously at the Northeast Crater and one or both of the
other two was fully valid for the period on which the knowledge of the
authors was based. However, soon after publication of "Mount Etna"
the dynamics of the summit crater complex proved to have become much
different from before. In the last 15-20 years the interactions between
the vents in the summit area have become much more complicated. The
Southeast Crater has established itself as the most active and productive
of the four summit craters, and it seems due to become the highest point
on Etna within the foreseeable future.
Much more space would be given to the description of paroxysmal eruptions
at the summit craters, of which more than 120 (one hundred twenty!)
have occurred in the years since publication of "Mount Etna",
especially since 1995. This particular type of activity is certainly
a result of the changing dynamics of magma ascent within the volcano.
Similarly the shift from frequent flank eruptions to continuous and
vigorous summit activity after the 1991-1993 flank eruption would be
discussed, as such changes in the behavior of the volcano appear to
be more common and cyclic than was thought in 1985.
Maybe the chapter that would look most different in a new version of
the book is the one on internal plumbing and geophysical monitoring
of Etna. In fact, this subject would be sufficient to make up a book
on its own. The network of modern instruments (seismographs, tiltmeters,
gravity stations etc.) has been vastly extended, and a voluminous flow
of data (much of them arriving in real time) has accompanied the various
eruptive - or better say, magmatic - events of the past 15-20 years.
These data are providing new insights into the structure of the volcano
and into the formerly highly mysterious processes related to the storage
and movement of magma at depth. Recent research has shown that apart
from a large, and possibly long-lived, magma storage area at 20-25 km
depth under Etna there are secondary zones where magma accumulates at
least temporarily. Such more shallow reservoirs may play a critical
role in determining the shift from periods with frequent flank eruptions
to periods when eruptive activity is limited to the summit area, and
thus the monitoring of magma accumulation in these storage areas could
give more clues about when flank eruptions might resume, and how much
magma would be available for eruption.
These ground-based techniques are now complemented by very powerful
tools placed in orbit around the Earth. Among the most spectacular and
precise of these are GPS (Global Positioning System) and SAR interferometry,
which are capable of depicting the deformation of volcanic edifices
at very high resolution. Deformation of Etna is extensive and complex,
and while part of its is surely related to magma movement at depth,
a significant portion is caused by local and regional tectonics and
volcano instability, and it can be assumed that some or all of these
factors are intimately interwoven.
The eruptions in 2001 and 2002-2003 have brought the revival of a concept
nearly forgotten at the time, developed in the 1950s by the late Alfred
Rittmann, who distinguished flank eruptions at Etna into "lateral"
(where the magma is transferred from the central conduits into fissures
extending radially into the flanks) and "eccentric" (where
the magma rises through a conduit independent from the central conduit
system). Such eruptions were extremely rare during the 20th century,
but eccentric activity was significant in the 2001 and 2002-2003 eruptions,
and probably also during numerous flank eruptions in the past. One key
characteristic of such eccentric eruptions is that they arise from closed
systems, which means that virtually no pre-eruptive degassing takes
place, in contrast with lateral eruptions, whose magma has already degassed
through the summit craters. Eccentric eruptions are therefore much more
explosive than lateral eruptions, as was experienced first-hand by many
people living near Etna during the eruptions in 2001 and 2002-2003.
Eccentric eruptions provide a challenge to previously established models
about the magmatic plumbing system and the dynamics of Etnean flank
eruptions, and their vigorous reappearance at the beginning of the current
millennium might indicate that the plumbing system is changing right
before our eyes (or, more litterally, below our feet).
Also in the past 15-20 years the attitude towards hazard mitigation
and response to eruptions has changed to some degree. It appears that
now the authorities and the population of a region threatened by future
eruptions would no longer simply wait and see what happens. With a set
of conditions allowing - such as eruption site, effusion rate, free
space where lava could be diverted to - measures will likely be undertaken
to protect inhabited zones or valuable agricultural areas from invasion
by lava flows. The diversion efforts during the 1983 and 1991-1993 flank
eruptions, non regarding their strongly disputed success, have served
to break the (mental and legal) barriers which prevented any protective
action in the past. Yet they have created an attitude in the local population
that cannot be considered too positive: it is now assumed by many residents
in areas potentially at rish that during any dangerous eruption in the
future, "they will divert the lava and nothing bad will happen."
The rapid construction of earth barriers during the eruptions of 2001
and 2002-2003 has certainly served to protect and save structures of
enormous value in the tourist pool around the Rifugio Sapienza. Yet
those eruptions were not of the most evil kind that could happen. Eruptions
at lower altitude, and especially on the southern and southeastern sides
of the mountain, would create a terrible dilemma, which might become
reality in the not-too-distant future.
The views expressed in the preceding paragraphs are not meant as criticism,
but instead indicate how vigorously Etna and the understaning of this
volcano have evolved since 1985. The only true criticism to be expressed
about "Mount Etna" regards a rather minor point: the consistent
wrong spelling of the name of one of the pioneers of Etna-related volcanology.
It reads like this: "vön Waltershausen". Actually, the energetic
German baron of the mid 19th century should be cited as "Sartorius
von Waltershausen". However, the fact that this is one of the few
factual errors in the book underlines its high level of accuracy.
Among late-1980s publications about Etna, one book merits special attention.
This is "Sur l'Etna" (I
own the German version, published in 1988, and have no information if
there's also an English version) by the late Haroun
Tazieff, a scientist who visited the volcano dozens of times
in nearly 50 years and surely was more intimately acquainted with it
than many other foreign scientists, mostly because he knew Etna long
before. Tazieff saw the large flank eruption of 1950-1951 and the subsequent
long-lived summit eruptions that lasted from 1955 until 1971. He also
visited Etna during many of the flank eruptions that occurred from 1971
Who expects a keen analysis of the wealth of impressions collected during
these many years in Tazieff's book must remain pretty put off. Rather
than elaborating the data (how much did he really collect?) and memories,
Tazieff presented a kind of "autobiographical notes" concerning
his experiences on Etna and other volcanoes. Much of this book is anecdotal,
and to a lesser degree scientific. Large space is devoted to polemic
remarks about what Tazieff considered "would-be volcanologists",
meaning most of his colleagues working on Etna. However, a general weak
point in Tazieff's reasoning and public behavior was that most of the
controversy was carried out via the mass media, not in scientific publications,
which cost him a serious portion of prestige in the volcanological community.
Although some of the numerous photographs (many in color) in Tazieff's
book are quite spectacular, many others could have been left out, for
they are blurred or reproduced badly. This is certainly not the best
Tazieff could have made of it; nonetheless it represents an aspect in
Etnean volcanology that merits consideration by any one interested in
the volcano and the way it is, and has been, studied.
post-1985 surge in Etna-related studies is in part reflected in a small
collection of short papers resulting from a meeting in the UK in 1996
entitled "Etna: 15 years on".
This volume, which is probably not very easy to locate outside the UK,
follows the tradition of the "UK Research on Mt Etna" publications
of the 1970s and early 1980s. In the same year (1996) several papers
dealing with structural instability at Etna were included in a classic
volume of the Special Publications of the Geological Society of London
(Volcano instability on the Earth and the other
planets, edited by W.J. McGuire and others, Special Publication No.
110), focusing on another recently developed theme in modern
research at Etna (as well as at many other volcanoes). Amongst others,
it contains a paper written by Rust and Neri, which discusses the location
and extent of volcanic spreading on Etna's unstable eastern to southern
flanks, a concept that has proved fundamental in the current dynamics
of the volcano and its activity.
year 1996 also marks the publication of the only fairly recent book
entirely dedicated to Mount Etna: "L'Etna
et le monde des volcans" by Tanguy and Patanè.
Both authors - Tanguy is a petrologist and paleomagnetist at the Université
VI Paris and at the Institut de Physique du Globe Paris, Patanè
is more specialized in seismology and works at the Dipartimento di Scienze
Geologiche of the University of Catania - have been studying Etna since
30-40 years and thus their level of experience can be compared to that
of Guest and his coauthors, only that their book was published more
than a decade later than "Mount Etna: The Anatomy of a Volcano".
Patanè is moreover privileged to be one of the few authors cited
thus far who is native Sicilian and lives at Etna. "L'Etna"
is a valuable contribution which renders a reasonably comprehensive
idea about modern concepts in Etna-related volcanology. Yet it will
remain inaccessible to a large fraction of interested readers, because
so far it is only available in French.
The structure of the book is slightly different from that of "Mount
Etna". The first chapter, after providing two introductory paragraphs,
presents the physical geography of the mountain, its vegetation, the
eruptive products, volcanic landforms, and eruptive styles. This chapter
is entitled "A volcano and Man", but only part of it describes
the life around the volcano, focusing on the "belt" of towns
and villages around Etna and their history. The chapter provides an
overall impression of Etna as an environment and as an active volcano.
The second chapter arcs from general considerations on the structure
of the Earth's mantle as the source of magma, the concept of plate tectonics
and various types of volcanic eruptions in general to the plate tectonic
setting of Etna, before the authors express their hypothesis for the
origin of Etna - a hot spot, or a mantle plume - and then detail the
geological evolution of the volcano. The mantle plume hypothesis is
one of many theories about the conditions that lead to the intense magmatism
at Etna, and probably has something reasonable to it, even though it
is possible that this is not the only reason why Etna is there.
The following two chapters are basically a review of the historical
eruptions of Etna in the light of the growth of volcanology as a science.
In chapter 3, Tanguy illustrates ho historical documents reporting eruptions
can be checked by applying paleomagnetic studies on lava flows allegedly
produced by historical eruptions. This approach has led to a series
of corrections in the list of historically documented eruptions, which,
however, have not been unanimously accepted, although they should be
considered seriously unless other dating techniques provide more reliable
data. Based on the paleomagnetic studies carried out on numerous lava
flows, the historical eruptions record is reviewed, and some eruptions
are discarded or attributed to other - mostly older - dates. The long
and well readable voyage through the long list of Etna's eruptions from
the Classical Age through the 1990s ends with the 1991-1993 eruption
(an appendix provides more quantitative data, including volumes, of
all documented eruptions, ending with the first year of the summit eruptions
initiated in 1995).
The fifth, and probably most innovative, chapter of the book takes the
reader to the rapidly evolving world of geophysical and geochemical
monitoring. Various methods - seismology, ground deformation measurements,
gravimetry, geoelectric methods, temperature and gas measurements, geomagnetism,
remote sensing, and mineralogy-petrography - are presented as means
to identify possible eruption precursors. The last section of the chapter
deals with volcanic hazards, eruption prediction and protective measures
(lava flow diversion). Here the authors describe the two widely publicized
and discussed interventions carried out in 1983 and 1992 to divert lava
flows that presented a more or less real threat to inhabited areas.
Tanguy and Patanè strongly criticize the way in which both operations
were justified by their authors and doubt their efficiency, pointing
to the absence of a serious threat in the 1983 case, and the fact that
in 1992 the effusion rate droped significantly almost at the same as
the diversion was carried out, rendering the effort - in the authors'
opinion - essentially unnecessary.
The last bit of the main section of the book is entitled "Conclusions"
and has a subtitle: "Toward a model of the great volcano".
Here the various eruptive mechanisms displayed at Etna are defined and
then a volcano-tectonic model of the volcano is presented, which envisages
the magmatic dynamics at varous stages during its evolution.
"L'Etna" has various additional sections. The first is a volcanological
glossary, useful for readers without an extensive volcanological background
knowledge. It is followed by a reference list (153 entries), a few historical
sources, and hints to other general volcanological reference works (two
in French, the third is the Smithsonian's monumental 2nd edition of
Volcanoes of the World, 1994). Two tables then give quantitative data
and volumes for some eruptions, calculated by John Murray. A third table
contains demographic data of the principal population centers around
Etna since 1824. A map showing most of the historical lava flows of
Etna has the corrected dates of some flows (based on paleomagnetic studies)
and forms the end of the book.
As "Mount Etna", this book appeared at a time when studies
on flank instability and volcano spreading were still in a very early
stage, and thus very little mention is made of this concept, although
two landmark papers (Borgia et al. 1992, and Lo Giudice and Rasà
1992) had already been published. Equally, eccentric eruptions are not
discussed as a distinct type of flank eruption (as was generally the
case in all publications prior to the 2001 eruption), but in the light
of the recent events, they are certainly viewed as an essential feature
in Etna's dynamics by at least one of the authors (J.-C. Tanguy, personal
"L'Etna" is vivid with numerous good color photographs, taken
mostly by Tanguy, which illustrate the text well. The book, although
partially focused on different issues than "Mount Etna", is
certainly a highly valid contribution and would merit to be published
in an English version; it deserves a place in the bookshelf of anyone
interested in Etna, next to "Mount Etna".
the time of the latest update of this page (October 2003), a new publication
concerning Italy's volcanoes is just out, which might temporarily solve
the problem of geological field guides becoming obsolete. It's the great
return on the scene of some of the grand masters of Etna-related science:
Guest, Cole, Duncan and Chester, with a book entitled "Volcanoes
of Southern Italy" (published by the Geological
Society of London in the Geological Society Earth in View series. I
do not yet own a copy of this book, and therefore cannot comment on
it, but it is all but certain that this will to some degree be the long-awaited
followup to "Mount Etna: The Anatomy of a Volcano", in addition
to the information provided about all other young volcanic areas of
the same reasons as in the preceding case, I cannot yet provide any
review of another recently published book that in part concerns Mount
Etna: "Volcanoes of Europe",
written by Scarth and Tanguy and out in the bookshops since 2001. I
own no more than the Table of Contents, Preface and Introduction to
this book, along with the introductory paragraphs to the various volcanic
areas discussed in the book. The file was posted for promotional reasons
on the the publisher's web site (Terra
Publishing) and yields an impression what the book is all about,
and the style in which it is written. Mount Etna is covered in a chapter
20 pages long, and as in the case of "Volcanoes of Southern Italy",
it will be probably a precious update on Etna-related science united
in a comprehensive text.
another book falling into more or less the same category as the previous
two, "Italian Volcanoes"
by Kilburn and McGuire appeared in 2002 at Terra
Publishing. Kilburn has for a long time worked with the Guest-Duncan-Chester-and-others
group and, together with McGuire, belongs to the eminent foreign Etna
experts, whose work over the past few decades has given countless valuable
contributions to the current understanding of this volcano. Mount Etna
is featured in a chapter some 40 pages long, covering the geological
evolution of the volcano, the 1669 eruption and the attempts to divert
the lava flow from Catania during that event, the petrography and petrology
of Etna's rocks, and the magmatic plumbing system. Field excursions
are proposed to the summit area, the Valle del Bove, the lower flanks
and Ionian coast, and other areas of interest nearby. Like in the case
of "Volcanoes of Southern Italy" and "Volcanoes of Europe",
I expect this book to provide much more up-to-date information than
the publications discussed earlier, although it came just a tiny little
bit too early to embrace the overwhelming amount of new data and new
insights provided by the eruptions in 2001 and 2002-2003. Its information,
as seen in a promotional pdf file made available by the publisher, includes
the impressive summit eruptions that preceded the 2001 eruption, but
not that flank eruption itself.
of the other publications about Etna - interesting though they are -
are scattered widely in the scientific literature. It is impossible
to discuss them all here (for a constantly growing but by no means complete
list see the References page), although
it is c.
Two booklets dealing with the 1989 and 1991-1993 eruptions of Etna should
be mentioned first. Both were edited by Barberi and others in 1990 and
1992, respectively, and are probably difficult to find for most interested
readers. The second one has, however, been condensed into a paper published
by Barberi and others in the Journal of Volcanology and Geothermal Research
"Etna: The 1989 eruption"
is an extremely important publication since it presents results of the
observation and monitoring of the dramatic 1989 eruption and associated
phenomena, one of the most closely monitored flank eruptions of Etna
so far. "The 1989 eruption" impressively demonstrates how
multidisciplinary studies carried out by scientists from many collaborating
institutions are able to produce a wealth of insight into the dynamics
of an eruptive event. The 1989 eruption was particularly complex and
dramatic, yet it was captured in unprecedented detail, bringing Etna-related
volcanology to a level with studies at other volcanoes which are thoroughly
monitored since long time.
The booklet on the 1991-1993 eruption (entitled "L'eruzione
1991-1992 dell'Etna e gli interventi per fermare o ritardare l'avanzata
della lava") is presented in a similar manner, but its
content differs significantly from that of the previous one. Firstly,
it was published while the eruption it deals with was still under way
(1992). Furthermore the eruption was completely different in its characteristics
from the 1989 one. Ample space is given to the description and justification
of the measures carried out to divert the lava flow which threatened
the town of Zafferana. In order to explain the need for such measures,
the authors vastly exaggerated the volume of lava emitted thus far (which
was repeated, in even larger dimensions, in the 1993 paper by Barberi
et al., in the Journal of Volcanology and Geothermal Research). The
issue is clearly biased by the viewpoint of the authors, and thus represents
an opinion rather than an objective observation, which under the circumstances
is understandable. The booklet, together with the following papers by
Barberi and others in the Journal of Volcanology and Geothermal Research
(1993) and in Acta Vulcanologica (1994) are interesting to read, but
for a full understanding of the events of 1991-1993 the interested reader
should compare them to the opinions expressed on that problem by other
scientists (Tanguy et al., 1996; Murray et al., 1997; Calvari et al.,
a more general level, scientific papers about Etna appear frequently
in the Italian journal Acta Vulcanologica (which demands submitted manuscripts
be written in English), and less frequently in the Journal of Volcanology
and Geothermal Research and Bulletin of Volcanology. The remainder is
distributed in the wealth of geologically oriented journals and occasional
special publications. Particular attention should be given to papers
written by John Murray and Bill McGuire and their respective collaborators,
in addition to the previously mentioned working group including Guest,
Duncan, Pinkerton and others. Many Italian scientists have as well appeared
on the scene and have begun to publish busily, as will be seen on the
References page. Much of this new work by Italian scientists will be
condensed in a special volume of the American Geophysical Union, due
for publication sometime during 2004.
on the eruptive activity of Etna are available in various sources, some
of them (the most up-to-date) on the internet. Yearly summaries appear
in the Bulletin of Volcanic Eruptions, published by the Volcanological
Society of Japan and added as a supplement to the Bulletin of Volcanology.
However, the most recent issue describes eruptions in 1993, and more
recent issues have apparently been delayed. Other summaries generally
covering 3-4 years are periodically published by the Italian Working
Group on Volcanology (GNV; now part of the re-organized Istituto Nazionale
di Geofisica e Vulcanologia INGV) in Acta Vulcanologica and in the Bollettino
di Geofisica Teorica ed Applicata. More frequent eruption reports appear
in the monthly Bulletin
of the Global Volcanism Network of the Smithsonian Institution;
between 1998 and 2001 many of them were compiled by Behncke, before
regular reporting was taken over by the Catania section of the Istituto
Nazionale di Geofisica e Vulcanologia.