Catastrophic 1638 earthquakes in Calabria southern Italy

Catastrophic 1638 Earthquakes In Calabria Southern Italy-Free PDF

  • Date:01 Jan 2020
  • Views:94
  • Downloads:0
  • Pages:20
  • Size:1.45 MB

Share Pdf : Catastrophic 1638 Earthquakes In Calabria Southern Italy

Download and Preview : Catastrophic 1638 Earthquakes In Calabria Southern Italy


Report CopyRight/DMCA Form For : Catastrophic 1638 Earthquakes In Calabria Southern Italy


Transcription:

ETG 1 2 GALLI AND BOSI PALEOSEISMOLOGY OF LAKES FAULT 1638 EARTHQUAKE ITALY. The Apennines formed above a west dipping subduction. zone and consist of a thrust belt foredeep system which. migrated eastward as a response to the flexure hinge retreat. of the subducting foreland lithosphere This retreat was. characterized by slip vectors largely exceeding the average. plate convergence rate in the Central Mediterranean region. during Neogene and Quaternary times Patacca and Scan. done 2001 and references therein Specifically the Cala. brian arc lies above a NW dipping subduction slab i e. Ionian oceanic lithosphere well characterized by a Benioff. plane Amato et al 1993 and extending at least 500 km. into the astenosphere below the southern Tyrrhenian Basin. The latter is commonly considered the back arc basin of the. Apenninic subduction its ages being younger when moving. eastward Gueguen et al 1997 and references therein The. Neogene Quaternary evolution of the Calabrian arc, induced a zone of crustal disequilibrium at the boundary. between the uplifting Aspromonte Sila mountain chain. 25 45 km thick continental crust Ghisetti and Vezzani. 1982 and the subsiding Tyrrhenian basin 10 km thick crust. of suboceanic composition Figure 2 Finetti and Morelli. 1973 causing extensional faulting in the imbricate systems. of the thrust belt since lower Pliocene time As a result a. series of elongate N S and NE SW trending basins formed. on the inner margin of the belt Crati Valley Mesima Valley. Gioia Tauro Santa Eufemia and Messina Strait basins. Figure 1 bordered respectively by primary east and NW. dipping high angle normal faults along the Tyrrhenian west. coast of southern Italy Tortorici et al 1995 Galli and. Bosi 2002 On the other hand active thrusting is restricted. in a narrow band along the eastern Apenninic front inset A. in Figure 2 as suggested by geophysical profiles Finetti. and Morelli 1973 Barchi et al 1998 and instrumental. seismicity,Figure 1 Shaded relief of Calabria showing both. 7 Starting from middle Pleistocene Calabria was rap. historical and instrumental seismicity respectively from. idly uplifted as suggested by the deposition of thick sandy. Working Group CPTI 1999 and courtesy of I Guerra, and conglomeratic bodies of deltaic or littoral environment. University of Calabria The latter is mainly confined in the. directly overlaying marine clays Moretti and Guerra. upper crust rhombs depth 20 km with few events, 1997 These deposits are found at elevation of 400 m. localized at greater depth depth 40 50 km square, asl within the extensional basins i e Crati half graben.
symbols The empty circle in Sila is our proposed epicenter. basin whereas Pliocene Pleistocene sediments and con. for the 9 June 1638 event Bold lines are known active. temporary continental paleosurfaces may reach 1400 m asl. faults 1 Castrovillari 2 Crati 3 Cecita Lake 4 Lakes 5. in the raised blocks of Sila Serre and Aspromonte,Piano Lago Savuto 6 Lamezia Catanzaro Santa Eufe. According to some authors Westaway 1993 van Dijk,mia Feroleto 7 Serre 8 Cittanova 9 Delianova Armo. and Scheepers 1995 the rapid uplift and the extensional. Reggio Calabria Modified from Galli and Bosi 2001, 5 In this paper we focus mainly on the June shock area Table 1 Parameters of the Main Shocks of March and June. both reanalyzing all the available historical sources and by Seismic Sequence According to Working Group CPTI 1999 a. means of geological and geomorphological field survey. Inside a wide area indicated by the contemporary sources Date Area Coord Io Imax Me. we individuated a previously unknown fault whose footwall Working Group CPTI 1999. March 27 Calabria 39 03 16 28 11 11 6 98, dams small and large streams creating lakes and ponds June 8 Crotonese 39 28 16 82 9 5 10 6 78. Lakes fault LF We opened four trenches across this fault. which show evidence for repeated displacement events dated This paper. back to the 1638 and to previous unknown earthquakes March 27 Savuto basin 39 11 16 27 11 11 6 8. March 28 Western Serre range 38 68 16 23 9 5 10 6 6. March 28 Santa Eufemia plain 38 96 16 26 11 11 6 6. 2 Geological and Seismotectonic Framework of June 9 Eastern Sila 39 22 16 57 11 9 5 6 7. Calabria The bottom of the table anticipates the results gathered in this paper Me. is the Macroseismic Equivalent Magnitude estimated by using the program. 6 Calabria is the southern termination of the Apennine Boxer Gasperini 1999 Due to cumulative damage effects we. peninsular chain resting in the toe of the Italian boot consider the Me of the March events a maximum value. GALLI AND BOSI PALEOSEISMOLOGY OF LAKES FAULT 1638 EARTHQUAKE ITALY ETG 1 3. Figure 2 Interpretative W E geological cross section through northern Calabria from the Tyrrhenian. Sea to the Ionian Sea Black stars indicate the possible hypocenters of the two 1638 main shocks. occurred within the extending upper crust of the Calabrian arc see inset A for location modified after. Van Dijk and Scheepers 1995, faulting in the Calabrian Arc during late Pleistocene to cene Holocene deposits are known High rates of Upper.
Recent are a result of the isostatic rebound that occurred Pleistocene vertical slip 0 6 0 9 mm yr Tortorici et al. when the detached remnants of the ruptured slab started to 1995 are mainly inferred from geomorphic features con. sink whereas the nondetached portion rapidly unbent and sisting of deeply eroded relict fault facets that were likely. elastically bounced upwards e g Figure 2 For this formed during an earlier time of higher rates of activity On. debated issue see also criticism in the study of Giunchi the other hand the lack of conclusive evidence of active. et al 1996 tectonic along these faults could be explained by their. moderate historical seismicity M 6 although we might. 2 1 Overview of Seismicity and Seismogenetic Faults have lost a strong event in the short historical record. of Northern Calabria 10 Major problems arise in the southern prosecution of. 8 Calabria is one of the most seismic areas of the the Crati plain high Crati high Savuto basins where M 6. Mediterranean region and has been struck in the past by earthquakes did occur 27 March 1638 and 10 April 1870. the most catastrophic earthquakes ever occurred in Italy In but no active structures have been yet clearly identified. fact at least 19 earthquakes with M 6 occurred since 91 Piano Lago and Savuto Decollatura normal faults 7 in. B C between the Messina Strait and the Crati Valley the Figure 3 Moretti 2000. last ones being the disruptive 1905 Ms 7 5 Mt Poro and 2 1 2 Central and Eastern Sector. 1908 Ms 7 3 Messina earthquakes parameters derived 11 As for the eastern side of the region few strong. from Working Group CPTI 1999 Figure 1 Although the events occurred along the Ionian slopes of Sila Apart from. Italian seismic catalogue spans over the past 2 ka being the 9 June 1638 the epicenter of which has been shifted. roughly complete for destructive earthquakes in the past westward in this paper they are the 1832 Me 6 5 and. 7 10 centuries Stucchi and Albini 2000 almost all the 1836 Me 6 2 earthquakes Me is the Macroseismic. Calabrian recorded events are concentrated in less than 3 Equivalent Magnitude evaluated by Working Group CPTI. centuries between 1638 and 1908 and they often occurred 1999 by using the Boxer program in the study of. within a few months or years of one another e g March Gasperini 1999 At present no hypotheses concerning. and June 1638 February March 1783 and 1905 1908 or their causative faults exist although the Highest Intensity. within 1 century southward migrating sequence of Crati Datapoints Distribution HIDD and some historical. Valley of 1767 1835 1854 and 1870 see triangle head accounts could suggest a relationship between the 1836. arrow in Figure 1 Differently from southern Calabria event and an E W lineament dashed line 4 in Figure 3 see. where all major earthquakes have been related to primary also Corigliano Rossano lineament in the study of Moretti. NE SW normal faults 7 9 in Figure 1 see Tortorici et al 2000. 1995 Jacques et al 2001 Galli and Bosi 2002 the 12 The Sila massif is instead a historically silent closed. northern Calabria seismogenetic framework is still poorly window on the seismotectonics of the region Only recently. constrained and debated the distribution of the instrumental seismicity Figure 1. 2 1 1 Western Sector courtesy of Prof I Guerra University of Calabria showed. 9 As shown in Figure 1 the sector resting between the scattered M 4 5 events even inside the massif itself. Catanzaro and the Sibari straits is affected by a M 6 Nevertheless the lack of historical seismicity in the Sila. seismicity which is commonly linked to the Crati basin massif should not imply the nonexistence of active struc. normal faults 2 in Figure 1 See also focal mechanisms 1 tures An example is given by the NNW striking Cecita. and 6 in Figure 3 For the Crati faults total length about Lake fault CLF 5 in Figure 3 newly appeared in the. 40 km 1 3 in Figure 3 Tortorici et al 1995 which drove literature Sorriso Valvo and Tansi 1997 and defined. the opening of the Crati half graben basin during lower active during the Pleistocene by Moretti 2000 or by the. middle Pleistocene no displacements of any upper Pleisto unknown LF 6 in Figure 3 which is responsible for. ETG 1 4 GALLI AND BOSI PALEOSEISMOLOGY OF LAKES FAULT 1638 EARTHQUAKE ITALY. Figure 3 Shaded relief of northern Calabria Our HIDD of 1638 events is shown together with that of. 1832 and 1836 modified from Boschi et al 2000 and Monachesi and Stucchi 1998 respectively. intensities proportional to dimension of circles see symbols in legend Note the vast HIDD scattering of. the June 1638 event compared to the March one Dashed ellipses A C show tentatively the epicentral. areas of the three main shocks occurred between 27 and 28 March 1638 Blue stars are the location of the. main instrumental events ML 4 4 5 recorded by the local seismic network of Cosenza University. courtesy of I Guerra with related focal mechanisms 1 20 February 1980 ML 4 3 2 24 January. 1990 ML 4 5 3 24 April 1991 ML 3 9 4 26 March 1994 ML 4 1 5 27 April 1996 ML 4 0. 6 18 October 2001 MW 4 4 For the northernmost event 27 April 1996 ML 4 we show also the. swarm distribution green area which fits with the NNW SSE plane solution Red lines are the primary. possibly active faults of the region teeth on downthrown block as deduced from literature e g. Tortorici et al 1995 and from our data 1 Fagnano Castello 2 San Marco San Fili 3 Montaldo. Rende 4 Rossano Calopezzati 5 Cecita Lake 6 Lakes 7 Piano Lago Decollatura 8 Feroleto Santa. Eufemia 9 W Serre Blue lines 10 and 11 represent the Marchesato and Mt Fuscaldo faults according to. Moretti 2000, GALLI AND BOSI PALEOSEISMOLOGY OF LAKES FAULT 1638 EARTHQUAKE ITALY ETG 1 5. the June 1638 earthquake as described in detail in the over the zone struck by the earthquakes while the first. following chapters and main shock occurred effectively at the sunset of 27. 13 On the other hand according to Moretti 2000 the March the second and third area were hit only on the Palm. primary faults of the Ionian slope of Sila are the Marchesato Sunday 28 March when he personally witnessed the. and Mount Fuscaldo faults 10 and 11 in Figure 3 which disruption and the sinking of Santa Eufemia see location. drove the lowering of Ionian block and which would have in Figure 3 The day after the earthquakes of 27 Palm. been also the causative structures of the June 1638 event Sunday between Pizzo and Santa Eufemia we heard a. However apart from the 100 m offset of Lower Pleistocene rumbling sound like a thunder quite hollow which seemed. deposits along the Mt Fuscaldo fault Moretti 1993 no coming from a far place but that was growing louder as. displacements of any upper Pleistocene Holocene deposits approaching nearer until it stopped in the underground of. are known the place on which we stood And just there it struck the. 2 1 3 Southern Sector Earth with a so violent shake that everyone being unable to. 14 The southern edge of both Sila massif and of Coastal stand was compelled to catch hold of a branch or a sea. Range is the Feroleto Santa Eufemia fault 8 in Figure 3 shrub And there exactly in that moment occurred the. highlighted by a prominent south facing fault scarp com ruin of the celebrated town of Santa Eufemia As the. posed by several discontinuous E W and ESE WNW Nature s fury lessened and we cast a glance around we. strands with a sinistral en echelon arrangement According saw the aforementioned town surrounded by a great. to Moretti 2000 the fault is related to a deep transform cloud But at three of the afternoon after the cloud lazily. structure Catanzaro fault Finetti and Del Ben 1986 and passed away we turned to look for the city but did not see. it offsets Upper Pleistocene Holocene terraces being it nothing but a dismal and putrid lake was seen where it. responsible for the northernmost main shock of the 1783 stood We looked about to find some one that could tell us. catastrophic sequence 28 March Me 7 of this sad catastrophe but could see no person Only an. astonished child sitting on the shore refusing the food. that we offered him seemed to point out with his fingers. 3 The 1638 Earthquake Sequence the catastrophe of Santa Eufemia Kircher 1665 trans. 15 As mentioned before the 1638 earthquakes hit the lated from Latin by the authors. active too is not associated to any historical earthquake of the Italian seismic catalogue this fact evidencing a long at least 1000 years elapsed time Our study permits 1 the relocation of the June 1638 earthquake inside the Sila massif the epicenter being shifted

Related Books