Stefano Branca | Istituto Nazionale di Geofisica e Vulcanologia (original) (raw)
Papers by Stefano Branca
Table 3: 14C dates of charcoals and bones came from the archeological sites of Etna region. Site ... more Table 3: 14C dates of charcoals and bones came from the archeological sites of Etna region. Site Period Archaeological Facies material Sample code C 14 age BP 1σ cal BC 2σ cal BC References
This study analyses the relationship between the pre-and protohistoric sites on the slopes of Etn... more This study analyses the relationship between the pre-and protohistoric sites on the slopes of Etna and the volcanic products, as well as the diverse settlement strategies in the different periods of prehistory. New C14 dating from significant excavations, in addition to those known from other Etnean sites, were performed with the aim of validating the chronology of the sequence of the different phases. A substantial concordance of the archaeological data with the volcanological ones has been found. It has been observed that a consistent human presence on Etna appears from the Middle Neolithic (5500 BC), after the sequence of eruptive events that marked the end of the Ellittico volcano (13550-13050 BC) and the formation of the Valle del Bove, and the subsequent debris and alluvial events on the eastern flanks of the volcano (7250-3350 BC). Human presence intensifies between the Late-Final Copper Age and the Early Bronze Age (2800-1450 BC), due to improvement in subsistence techniques and to the large presence of soils on lava flows suitable for sheep farming. The most recent phases of the Bronze Age are poorly represented, probably because of the concentration of the population in larger agglomerations (Montevergine and S. Paolillo at Catania, the Historical Hill at Paternò). The explosive eruptions taking place in this period seem to have had less impact on the settlement choices and have not affected the development of the sites over time.
The 1971 eruption represents a benchmark in the recent history of Etna volcano. From a volcanolog... more The 1971 eruption represents a benchmark in the recent history of Etna volcano. From a volcanological point of view, this eruption was characterised by complex intrusive dynamics associated with significant ground deformation that induced the activation of the Moscarello seismogenic fault and the formation of a new summit crater: the Southeast Crater. At the same time, the 1971 event marks an important change in the eruptive style and composition of the magma towards products richer in K. It is no coincidence that, over the next fifty years, there would be an increase in the frequency of summit and flank eruptions and associated output rate. From an historical viewpoint, the eruptive event of 1971 was the first important flank eruption studied by the International Institute of Volcanology: the analysis of the scientific articles on this activity reveals a greater multidisciplinary content in the descriptions and explanations of volcanic activity. Particularly important were the collaborations of British and French research groups that, together with their Italian colleagues, succeeded in giving a complete picture of the eruption and describing the state of knowledge on the Sicilian volcano. The multidisciplinary methodology used to study this eruption is still valid today.
Annals of Geophysics, 2021
The 1971 eruption represents a benchmark in the recent history of Etna volcano. From a volcanolog... more The 1971 eruption represents a benchmark in the recent history of Etna volcano. From a volcanological point of view, this eruption was characterised by complex intrusive dynamics associated with significant ground deformation that induced the activation of the Moscarello seismogenic fault and the formation of a new summit crater: the Southeast Crater. At the same time, the 1971 event marks an important change in the eruptive style and composition of the magma towards products richer in K. It is no coincidence that, over the next fifty years, there would be an increase in the frequency of summit and flank eruptions and associated output rate. From an historical viewpoint, the eruptive event of 1971 was the first important flank eruption studied by the International Institute of Volcanology: the analysis of the scientific articles on this activity reveals a greater multidisciplinary content in the descriptions and explanations of volcanic activity. Particularly important were the coll...
Annals of Geophysics, 2021
This study analyses the relationship between the pre- and protohistoric sites on the slopes of... more This study analyses the relationship between the pre- and protohistoric sites on the slopes of Etna and the volcanic products, as well as the diverse settlement strategies in the different periods of prehistory. New C14 dating from significant excavations, in addition to those known from other Etnean sites, were performed with the aim of validating the chronology of the sequence of the different phases. A substantial concordance of the archaeological data with the volcanological ones has been found. It has been observed that a consistent human presence on Etna appears from the Middle Neolithic (5500 BC), after the sequence of eruptive events that marked the end of the Ellittico volcano (13550 - 13050 BC) and the formation of the Valle del Bove, and the subsequent debris and alluvial events on the eastern flanks of the volcano (7250 - 3350 BC). Human presence intensifies between the Late-Final Copper Age and the Early Bronze Age (2800 - 1450 BC), due to improvement in subsistence ...
Frontiers in Earth Science, 2021
The structure of an active volcano is highly dependent on the interplay between the geodynamic co... more The structure of an active volcano is highly dependent on the interplay between the geodynamic context, the tectonic assessment as well as the magmatic processes in the plumbing system. This complex scenario, widely explored at Etna during the last 40 years, is nevertheless incomplete for the recent historical activity. In 1763 two eruptions occurred along the west flank of the volcano. There, an eruption started on 6th February and formed the scoria cone of Mt. Nuovo and a roughly 4-km-long lava flow field. Another small scoria cone, known as Mt. Mezza Luna, is not dated in historical sources. It is located just 1 km eastward of Mt. Nuovo and produced a 700 m long flow field. We focused on the activity of Mts. Nuovo and Mezza Luna for several reasons. First, the old geological maps and volcanological catalogues indicate that Mt. Mezza Luna and Mt. Nuovo cones were formed during the same eruption, while historical sources described Mt. Nuovo’s activity as producing a single scoria c...
World Geomorphological Landscapes, 2017
Journal of Volcanology and Geothermal Research, 2017
Advances in Volcanology, 2017
Bull Volcanol, 2005
Analysis of the historical records of Etna’s eruptive activity for the past three centuries shows... more Analysis of the historical records of Etna’s eruptive activity for the past three centuries shows that, after the large 1669 eruption, a period of about 60 years of low-level activity followed. Starting from 1727, explosive activity (strombolian, lava fountaining and subplinian) at the summit crater increased exponentially to the present day. Since 1763, the frequency of flank eruptions also increased and this value remained high until 1960; afterward it further increased sharply. In fact, the number of summit and flank eruptions between 1961 and 2003 was four times greater than that of the pre-1960 period. This long-term trend of escalating activity rules out a pattern of cyclic behaviour of the volcano. We propose instead that the 1670 2003 period most likely characterises a single eruptive cycle which began after the large 1669 eruption and which is still continuing.
Bulletin of Volcanology, 2015
Journal of Volcanology and Geothermal Research, 2015
Scientific reports, 2014
The flanks of volcanoes may slide in response to the loading of the edifice on a weak basement, m... more The flanks of volcanoes may slide in response to the loading of the edifice on a weak basement, magma push, and/or to tectonic stress. However, examples of stratovolcanoes emplaced on active landslides are lacking and the possible effects on the volcano dynamics unknown. Here, we use aeromagnetic data to construct a three-dimensional model of the clay-rich basement of Etna volcano (Italy). We provide evidence for a large stratovolcano growing on a pre-existing basement landslide and show that the eastern Etna flank, which slides toward the sea irrespective of volcanic activity, moves coherently with the underlying landslide. The filling of the landslide depression by lava flows through time allows the formation of a stiffness barrier, which is responsible for the long-term migration of the magma pathways from the coast to the present-day Etna summit. These unexpected results provide a new interpretation clue on the causes of the volcanic instability processes and of the mechanisms o...
Terra Nova, 2005
ABSTRACT Recent geological studies performed at Etna allow reassessing the stratigraphic frame of... more ABSTRACT Recent geological studies performed at Etna allow reassessing the stratigraphic frame of the volcano where distinct evolutionary phases are defined. This stratigraphic reconstruction was chronologically constrained on the basis of a limited number of U–Th and K–Ar age determinations whose uncertainty margins are sometimes too wide. For this reason, we successfully adopted at Etna the 40Ar/39Ar technique that allowed obtaining more precise age determinations. The incremental heating technique also gives information on sample homogeneity, and potential problems of trapped argon. Five samples were collected from stratigraphically well-controlled volcanic units in order to chronologically define the transition between the fissure-type volcanism of the Timpe phase to the central volcanism of the Valle del Bove Centers. Isotopic ages with an uncertainty margin of 2–4% have been obtained emphasizing that this transition occurred (130–126 ka) without significant temporal hiatus.
Table 3: 14C dates of charcoals and bones came from the archeological sites of Etna region. Site ... more Table 3: 14C dates of charcoals and bones came from the archeological sites of Etna region. Site Period Archaeological Facies material Sample code C 14 age BP 1σ cal BC 2σ cal BC References
This study analyses the relationship between the pre-and protohistoric sites on the slopes of Etn... more This study analyses the relationship between the pre-and protohistoric sites on the slopes of Etna and the volcanic products, as well as the diverse settlement strategies in the different periods of prehistory. New C14 dating from significant excavations, in addition to those known from other Etnean sites, were performed with the aim of validating the chronology of the sequence of the different phases. A substantial concordance of the archaeological data with the volcanological ones has been found. It has been observed that a consistent human presence on Etna appears from the Middle Neolithic (5500 BC), after the sequence of eruptive events that marked the end of the Ellittico volcano (13550-13050 BC) and the formation of the Valle del Bove, and the subsequent debris and alluvial events on the eastern flanks of the volcano (7250-3350 BC). Human presence intensifies between the Late-Final Copper Age and the Early Bronze Age (2800-1450 BC), due to improvement in subsistence techniques and to the large presence of soils on lava flows suitable for sheep farming. The most recent phases of the Bronze Age are poorly represented, probably because of the concentration of the population in larger agglomerations (Montevergine and S. Paolillo at Catania, the Historical Hill at Paternò). The explosive eruptions taking place in this period seem to have had less impact on the settlement choices and have not affected the development of the sites over time.
The 1971 eruption represents a benchmark in the recent history of Etna volcano. From a volcanolog... more The 1971 eruption represents a benchmark in the recent history of Etna volcano. From a volcanological point of view, this eruption was characterised by complex intrusive dynamics associated with significant ground deformation that induced the activation of the Moscarello seismogenic fault and the formation of a new summit crater: the Southeast Crater. At the same time, the 1971 event marks an important change in the eruptive style and composition of the magma towards products richer in K. It is no coincidence that, over the next fifty years, there would be an increase in the frequency of summit and flank eruptions and associated output rate. From an historical viewpoint, the eruptive event of 1971 was the first important flank eruption studied by the International Institute of Volcanology: the analysis of the scientific articles on this activity reveals a greater multidisciplinary content in the descriptions and explanations of volcanic activity. Particularly important were the collaborations of British and French research groups that, together with their Italian colleagues, succeeded in giving a complete picture of the eruption and describing the state of knowledge on the Sicilian volcano. The multidisciplinary methodology used to study this eruption is still valid today.
Annals of Geophysics, 2021
The 1971 eruption represents a benchmark in the recent history of Etna volcano. From a volcanolog... more The 1971 eruption represents a benchmark in the recent history of Etna volcano. From a volcanological point of view, this eruption was characterised by complex intrusive dynamics associated with significant ground deformation that induced the activation of the Moscarello seismogenic fault and the formation of a new summit crater: the Southeast Crater. At the same time, the 1971 event marks an important change in the eruptive style and composition of the magma towards products richer in K. It is no coincidence that, over the next fifty years, there would be an increase in the frequency of summit and flank eruptions and associated output rate. From an historical viewpoint, the eruptive event of 1971 was the first important flank eruption studied by the International Institute of Volcanology: the analysis of the scientific articles on this activity reveals a greater multidisciplinary content in the descriptions and explanations of volcanic activity. Particularly important were the coll...
Annals of Geophysics, 2021
This study analyses the relationship between the pre- and protohistoric sites on the slopes of... more This study analyses the relationship between the pre- and protohistoric sites on the slopes of Etna and the volcanic products, as well as the diverse settlement strategies in the different periods of prehistory. New C14 dating from significant excavations, in addition to those known from other Etnean sites, were performed with the aim of validating the chronology of the sequence of the different phases. A substantial concordance of the archaeological data with the volcanological ones has been found. It has been observed that a consistent human presence on Etna appears from the Middle Neolithic (5500 BC), after the sequence of eruptive events that marked the end of the Ellittico volcano (13550 - 13050 BC) and the formation of the Valle del Bove, and the subsequent debris and alluvial events on the eastern flanks of the volcano (7250 - 3350 BC). Human presence intensifies between the Late-Final Copper Age and the Early Bronze Age (2800 - 1450 BC), due to improvement in subsistence ...
Frontiers in Earth Science, 2021
The structure of an active volcano is highly dependent on the interplay between the geodynamic co... more The structure of an active volcano is highly dependent on the interplay between the geodynamic context, the tectonic assessment as well as the magmatic processes in the plumbing system. This complex scenario, widely explored at Etna during the last 40 years, is nevertheless incomplete for the recent historical activity. In 1763 two eruptions occurred along the west flank of the volcano. There, an eruption started on 6th February and formed the scoria cone of Mt. Nuovo and a roughly 4-km-long lava flow field. Another small scoria cone, known as Mt. Mezza Luna, is not dated in historical sources. It is located just 1 km eastward of Mt. Nuovo and produced a 700 m long flow field. We focused on the activity of Mts. Nuovo and Mezza Luna for several reasons. First, the old geological maps and volcanological catalogues indicate that Mt. Mezza Luna and Mt. Nuovo cones were formed during the same eruption, while historical sources described Mt. Nuovo’s activity as producing a single scoria c...
World Geomorphological Landscapes, 2017
Journal of Volcanology and Geothermal Research, 2017
Advances in Volcanology, 2017
Bull Volcanol, 2005
Analysis of the historical records of Etna’s eruptive activity for the past three centuries shows... more Analysis of the historical records of Etna’s eruptive activity for the past three centuries shows that, after the large 1669 eruption, a period of about 60 years of low-level activity followed. Starting from 1727, explosive activity (strombolian, lava fountaining and subplinian) at the summit crater increased exponentially to the present day. Since 1763, the frequency of flank eruptions also increased and this value remained high until 1960; afterward it further increased sharply. In fact, the number of summit and flank eruptions between 1961 and 2003 was four times greater than that of the pre-1960 period. This long-term trend of escalating activity rules out a pattern of cyclic behaviour of the volcano. We propose instead that the 1670 2003 period most likely characterises a single eruptive cycle which began after the large 1669 eruption and which is still continuing.
Bulletin of Volcanology, 2015
Journal of Volcanology and Geothermal Research, 2015
Scientific reports, 2014
The flanks of volcanoes may slide in response to the loading of the edifice on a weak basement, m... more The flanks of volcanoes may slide in response to the loading of the edifice on a weak basement, magma push, and/or to tectonic stress. However, examples of stratovolcanoes emplaced on active landslides are lacking and the possible effects on the volcano dynamics unknown. Here, we use aeromagnetic data to construct a three-dimensional model of the clay-rich basement of Etna volcano (Italy). We provide evidence for a large stratovolcano growing on a pre-existing basement landslide and show that the eastern Etna flank, which slides toward the sea irrespective of volcanic activity, moves coherently with the underlying landslide. The filling of the landslide depression by lava flows through time allows the formation of a stiffness barrier, which is responsible for the long-term migration of the magma pathways from the coast to the present-day Etna summit. These unexpected results provide a new interpretation clue on the causes of the volcanic instability processes and of the mechanisms o...
Terra Nova, 2005
ABSTRACT Recent geological studies performed at Etna allow reassessing the stratigraphic frame of... more ABSTRACT Recent geological studies performed at Etna allow reassessing the stratigraphic frame of the volcano where distinct evolutionary phases are defined. This stratigraphic reconstruction was chronologically constrained on the basis of a limited number of U–Th and K–Ar age determinations whose uncertainty margins are sometimes too wide. For this reason, we successfully adopted at Etna the 40Ar/39Ar technique that allowed obtaining more precise age determinations. The incremental heating technique also gives information on sample homogeneity, and potential problems of trapped argon. Five samples were collected from stratigraphically well-controlled volcanic units in order to chronologically define the transition between the fissure-type volcanism of the Timpe phase to the central volcanism of the Valle del Bove Centers. Isotopic ages with an uncertainty margin of 2–4% have been obtained emphasizing that this transition occurred (130–126 ka) without significant temporal hiatus.