Submarine Earthquake History of the Çınarcık Segment of the North Anatolian Fault in the Marmara ...

25 Pages·2017·2.36 MB·English

Submarine Earthquake History of the Çınarcık Segment
of the North Anatolian Fault in the Marmara Sea,
Turkey
Laureen Drab, Aurélia Hubert-Ferrari, Sabine Schmidt, Philippe Martinez,
Julie Carlut, Meriam El Ouahabi
To cite this version:
Laureen Drab, Aurélia Hubert-Ferrari, Sabine Schmidt, Philippe Martinez, Julie Carlut, et al.. Sub-
marine Earthquake History of the Çınarcık Segment of the North Anatolian Fault in the Mar-
mara Sea, Turkey. Bulletin of the Seismological Society of America, 2015, 105 (2A), pp.622-645.
￿10.1785/0120130083￿. ￿insu-01571132￿
HAL Id: insu-01571132
https://hal-insu.archives-ouvertes.fr/insu-01571132
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BulletinoftheSeismologicalSocietyofAmerica,Vol.105,No.2A,pp.622–645,April2015,doi:10.1785/0120130083
ı ı
Submarine Earthquake History of the Ç narc k Segment of
the North Anatolian Fault in the Marmara Sea, Turkey
by Laureen Drab,* Aurélia Hubert-Ferrari, Sabine Schmidt, Philippe Martinez,
Julie Carlut, and Meriam El Ouahabi
Abstract TheNorthAnatolianfault(NAF)intheMarmaraSeaisasignificanthaz-
ardforthecityofIstanbul.Theuseofpaleoseismologicaldatatoprovideanaccurate
seismic risk assessment for the area is constrained by the fact that the NAF system is
submarine; thus a history of paleoearthquakes can be inferred only by using marine
sediment cores. Here, a record of turbidites was obtained in two cores and used to
reconstruct the earthquake history along the Çınarcık segment, a main branch of the
NAF.Klg04wascollectedfromabermnorthofthefault,andKlg03waspositionedin
theÇınarcıkbasin,southofthefault.Thecoreswerecorrelatedusinglong-termgeo-
chemical variations in the sediment, and turbidites deposited simultaneously at both
sites were then identified. Radionuclide measurements suggest the most recent turbi-
ditewastriggeredbythe1894C.E.M 7.3earthquake.Weconcludethattheturbidites
w
identifiedatbothsitesare earthquakegenerated, basedontheirparticular sedimento-
logical and geochemical signatures; the correlation of turbidites at berm and basin
sites; and the match of the most recent turbidite with a nineteenth century historical
earthquake. To date older turbidites, we used carbon-14 and paleomagnetic data to
buildanOxCalmodelwithalocalreservoircorrectionof400(cid:1)50 yr.TheÇınarcık
segmentisfoundtohaverupturedin1509C.E.,sometimeinthefourteenthcentury,in
989 C.E., and in 740 C.E., with a mean recurrence interval in the range of 256–321
years.Finally,weusedtheearthquakerecordobtainedtoreviewtherupturehistoryof
the adjacent segments over the past 1500 years.
Introduction
ConstrainingtherecurrencerateofM >7earthquakes generallybeenidentifiedbasedontheirsynchronicityatdif-
w
thatthreatenthemegacityofIstanbulisproblematicbecause ferent sites and their distinctive sedimentological or geo-
thelateHolocenefaultsaresubmarine.Istanbul,with12mil- chemical signatures (Gorsline et al., 2000; Nakajima and
lion inhabitants, borders the Marmara Sea (Fig. 1a), a sub- Kanai, 2000; Shiki et al., 2000; Beck et al., 2007; Masson
marine pull-apart basin related to the North Anatolian fault et al., 2011; Drab et al., 2012). In the case of the Marmara
(NAF),amajorstrike-slipfaultthatrupturesinlargemagni- Sea,severalstudies(McHughetal.,2006;SarıandÇağatay,
tude earthquakes. Since the 1999 M 7.4 Izmit earthquake, 2006; Beck et al., 2007; Drab et al., 2012) revealed that its
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stresseshavefurtherincreasedintheeasternpartoftheMar- sediments contain a record of turbidites triggered by large
mara Sea (Hubert-Ferrari et al., 2000; Parsons et al., 2000; earthquakes. These turbidites have been used to constrain
Pondard et al., 2007). Understanding past ruptures of the thehistoryofearthquakesrupturingacrossagivendepocen-
NAFintheMarmaraSeaisthusakeyissueinassessingseis- ter (McHugh et al., 2006; Drab et al., 2012). The present
mic hazards for this area. studyshowsthatmarinesedimentcorescanbeusedtocon-
Subaqueous paleoseismology can reconstruct the his- strainpaleorupturesoftheNAFsegmentlocatedjustsouthof
tory of large earthquakes on submarine faults (Goldfinger, Istanbul and to evaluate the recurrence rate of large magni-
2011),asshakingassociatedwithlargeoffshoreearthquakes tude earthquakes in this area.
triggerssubmarinelandslidesandturbiditycurrents.There- Here, we apply subaqueous paleoseismology to two
sultingdepositscanbesampledbysedimentcoring,charac- gravity cores located in the Çınarcık basin of the Marmara
terized, and dated. Earthquake-generated turbidites have Sea (Fig. 1b). The Çınarcık basin is located ∼20 km to the
southofIstanbulandisnorthboundedbytheÇınarcıkfault,
*Now at Lamont Doherty Earth Observatory, Columbia University, 61 themainsegmentoftheNAF.Inthetwocores,weidentified
Route9WPalisades,NewYork10964;[email protected]. andcharacterizedturbiditedepositsusingtheirgrainsizeand
622
Submarine Earthquake History of the Çınarcık Segment of the NAF in the Marmara Sea, Turkey 623
Figure1. (a)GlobalgeodynamiccontextoftheAnatolianplatewithGlobalPositioningSystemvelocitiesfromReilingeretal.(2006).
ThelocationoftheMarmaraSea(shownin[b])isindicatedwithabox.(b)GeneraltectonicmapoftheMarmaraSea,crossedbytheNorth
Anatolianfault(NAF).Basins,highs,andmainsegmentsofthefaultareindicatedfromthewesttotheeastwithdifferentlines,andtheir
namesaregiveninthegrayboxtotheright.Thestudyarea(shownin[c])isdepictedwithabox.HistoricalearthquakeslocatedbyAm-
braseys(2002)arerepresentedwithrupturedatesanddots.(c)ThemapofÇınarcıkbasin.Locationofthetwostudiedcoresisrepresented
withrespecttotheÇınarcıkfaultsegment.Arrowsshowsedimentpathsforturbiditedeposits(Altınoketal.,2011).Thelinecrossingthetwo
coresrepresentsthetopographicprofilepresentedin(d).Whitecrossesrepresentthelocationofotherpublishedcoresdiscussedinthestudy.
(d)TopographicprofileofthenorthernpartoftheÇınarcıkbasin.TheprofilestartsclosetothecenteroftheÇınarcıkbasin.Thecolorversion
of this figure is available only in the electronic edition.
geochemical characteristics. We also used east Mediterra- geringmechanismsoftheturbidites.Radiogeniclead(210Pb)
nean-scale changes in sedimentation to correlate the two andcesium(137Cs)dataallowedustodateandcorrelatedthe
records toa reference corelocated ina nonturbiditedeposi- turbiditesatthetopofthesedimentcolumnswithrecenthis-
tional environment. We then investigated the possible trig- torical earthquakes. Radiocarbon dating (14C) combined
624 L. Drab, A. Hubert-Ferrari, S. Schmidt, P. Martinez, J. Carlut, and M. El Ouahabi
with paleomagnetic data enabled us to construct an age seismicity during the end of the thirteenth and fourteenth
model for the core Klg04 located in a berm in the Çınarcık centuriesintheMarmaraarea(AmbraseysandFinkel,1991).
faultscarp(Fig.1c,d)andtodateturbiditesoverthelast1500 The 989 C.E. earthquake principally affected the Istanbul
years.Finally,theNAFrupturebehaviorintheMarmaraSea region,withatsunamireachingthecity(AmbraseysandFin-
is discussed. kel, 1991; Altınok et al., 2011). Historical data predomi-
nantly locate the event in the Çınarcık basin (Ambraseys,
2002; Guidoboni and Comastri, 2005). Finally, the 740
Setting M 7.1C.E.earthquakewasassociatedwithalargetsunami
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(Altınok et al., 2011). It has been generally located in the
Tectonic and Paleoseismological Background
Çınarcıkbasin(Ambraseys,2002;GuidoboniandComastri,
The NAF is a major dextral strike-slip fault extending 2005), but some authors suggested an epicenter location in
over 1200 km in northern Turkey and in the Aegean Sea the Izmit Gulf or Central basin (McHugh et al., 2006; Ber-
(Barka and Kadinsky-Cade, 1988; Sengör et al., 2005) trandetal.,2011;Çağatayetal.,2012).Historicalinforma-
(Fig.1a).IntheMarmaraSea,theNAFaccommodatesadex- tionforolderagesislimited,butAmbraseys(2002)located
tral horizontal motion of 18:5 mm=yr (Kurt et al., 2013) the407C.E.and437C.E.earthquakesintheÇınarcıkbasin.
spread over a width of 130 km (Barka and Kadinsky-Cade, Based only onhistoricalreports, itis difficultto unam-
1988). Most of the deformation is localized on the northern biguouslyassociateanoffshoreearthquakewithagivensub-
branch of the NAF (Armijo et al., 2002), which crosses the marine fault (Table 1). Even studies combining historical
MarmaraSea.TheMarmaraSeais170kmlong,hasamaxi- datawithattenuationmodels(Parsons,2004)ordistribution
mumwaterdepthof1250m,andiscomposedofthreealigned ofslipdeficitandCoulombstressinteraction(Pondardetal.,
pull-apart basins separated by two topographic ridges (Le 2007)proposedifferentrupturescenariosacrosstheMarmara
Pichon et al., 2001; Armijo et al., 2002; Sarı and Çağatay, Sea. Subaqueous paleoseismological studies provide addi-
2006; Fig. 1b). tional constraints. Indeed, in the Marmara Sea, earthquake-
ThestudyfocusesontheÇınarcıkbasin,theeasternmost triggeredturbiditeshavebeendocumentedbyMcHughetal.
transform basin of the Marmara Sea (Fig. 1c). The (2006),SarıandÇağatay(2006),Becketal.(2007),andDrab
50 kmlong×18 kmwide basin is bounded to the north etal.(2012).InadditionMcHughetal.(2006)andDrabetal.
by the main segment of the NAF and to the south by a sec- (2012)foundthatlargeearthquakesrupturingtheboundingor
ondary normal fault system (Smith et al., 1995; Le Pichon crossingfaultofagivenbasinstronglyaffectitssedimentation
et al., 2001; Armijo et al., 2002). The main northern seg- buthaveminorornoeffectsonthenearbysedimentarybasins.
ment, here called the Çınarcık segment, runs at the base of Thus,aseriesofindividualseismoturbiditescanbelinkedtoa
a steep escarpment, 1000 m high (from 200 to 1200 meters specific earthquake rupture associated with large historical
belowsealevel[m.b.s.l.])and40kmlong.Thefaultischar- earthquakes.
acterized by composite strike-slip and normal motions
(Armijo et al., 2002).
Seismoturbidite Characteristics
Inthelast300years,theÇınarcıkbasinhasexperienced
severalM >6earthquakes(Ambraseys,2002;Fig.1a).The Ingeneral,turbiditesareofteninterpretedtohaveaseis-
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most recent 1963 C.E. M 6.3 earthquake occurred on the mic trigger because of their broad contemporaneous occur-
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southernfaultborderingtheÇınarcıkbasin(BulutandAktar, rence in a given setting (Goldfinger, 2011) and of their
2007; Fig. 1a). Presently, this is the only earthquake unam- particularsedimentologicalimprint.IntheMarmaraSea,the
biguously attributed to a fault in the Çınarcık basin. The geographical extent of turbidite deposits has been deduced
1894C.E.M 7.3earthquakehasbeenlocatedintheÇınar- by correlating different sediment cores or by using high-
w
cıkbasin(Parsons,2004;Hebertetal.,2005;Pondardetal., resolutionseismicsubbottomprofilesforimagingfinetrans-
2007)orintheIzmitGulf(Hubert-Ferrarietal.,2000;Am- parent layers related to turbidite deposits (McHugh et al.,
braseys,2002;McHughetal.,2006).Theassociatedtsunami 2006; Beck et al., 2007).
strongly affected the Prince Islands, south of Istanbul (Am- Seismoturbidites are generally distinctive from non-
braseys, 2002; Altınok et al., 2011). During the eighteenth earthquake-triggeredslopefailureturbiditesbecauseoftheir
century, there was a westward-propagating sequence of specific sedimentological and mineralogical imprints. They
earthquakesintheMarmaraSea(1719C.E.,1754C.E.,May arecharacterizedprimarilybycomplexlaminae(Shikietal.,
andAugust1766C.E.),butthecorrespondingfaultruptures 2000;McHughetal.,2011);sharpbasallayers(Shikietal.,
are poorly constrained. In 1509 C.E., a large earthquake 2000);multiplecoarsebasesenrichedwithshellsanddetrital
destroyed Istanbul; its epicenter has been located near the material, indicating multiple sources (Nakajima and Kanai,
city (Ambraseys, 2001, 2009), but it may have ruptured 2000; Bertrand et al., 2008; Goldfingeret al., 2008); varia-
eithertheÇınarcıkortheCentralfaults(GuidoboniandCo- tion in the composition of detrital material between each
mastri, 2005). Destruction associated with the 1343 C.E. event (Nakajima and Kanai, 2000); and abrupt changes in
earthquake was mostly on the western part of the Marmara sedimentary structures (Nakajima and Kanai, 2000; Shiki
Sea,butthisearthquakewasassociatedwithalargeburstof et al., 2000).
Submarine Earthquake History of the Çınarcık Segment of the NAF in the Marmara Sea, Turkey 625
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armara ıÇnar Izmit Izmit Centr ıÇnar ıÇnar ıÇnar
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ake Iz Iz Iz Iz Iz
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August1766 Ganosfault ğTekirda ııWestofÇnarck Ganosfault ğ–TekirdaGanosfault ğ–TekirdaGanosfault
1894 IzmitBay ııÇnarck EastofIzmitbasinIzmitBay ııÇnarck(southornorth)/IzmitoverlapııSouthÇnarck
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HistoricalEarthquake Ambraseys(20 etal.Bertrand(2011)ğetal.Çaatay(2012)etal.Drab(20GuidoboniandComastri(20etal.Herbert(2005)Hubert-Ferrarietal.(2000)etal.McHugh(2006) Parsons(2004) etal.Pondard(2007)
626 L. Drab, A. Hubert-Ferrari, S. Schmidt, P. Martinez, J. Carlut, and M. El Ouahabi
Seismoturbidites in the Marmara Sea have been distin- Thesedimentaryimprintsofthedifferentenvironmental
guishedfromother turbidites basedontheirparticulargrain changesaresummarizedinFigure2,usingdatafromthecore
size and geochemical characteristics (Sarı and Çağatay, Klg06 published in Drab et al. (2012) and the core MD01-
2006; Beck et al.,2007; Çağatayet al.,2012). The seismo- 2430 published in Vidal et al. (2010) and Valsecchi et al.
turbiditesdepositedintheCentralandTekirdağbasinshave (2012).ThetwocoresarelocatedontheMarmaraSeastruc-
the following specific characteristics (Drab et al., 2012): tural Western High, are devoid of anysignificant turbidites,
(1) they display nongradational changes in particles size and contain a continuous record of environmental changes.
andcoarsebasalpulse;(2)intermediatesilt-richlayersshow Drabetal.(2012)haveshownthattheseglobalenvironmen-
numerous thin parallel laminae and flaser-bed structures tal changes are synchronous in the different basins of the
linked to oscillating currents (Beck et al., 2007; Campos MarmaraSeaandcanbetrackedthroughx-rayfluorescence
etal.,2013);(3)sharpbasalsandlayersarecharacterizedby (XRF)measurements.Asaconsequence,commontimehori-
a decrease in bromine (Br) content, a relative increase in zons between sediment cores can be defined and used to
titanium(Ti),apeakinzirconium(Zr),andmagneticsuscep- match turbidites in a given depocenter.
tibility (Çağatay et al., 2012; Campos et al., 2013); and
(4) the turbidite is capped by a clayey silt layer. Turbidites
Coring Site and Methods
inducedbyearthquakesintheIzmitGulfhavethesamechar-
acteristics and show a large peak in manganese below the Two Kullenberg sediment piston cores, Klg03 and
baseoftheturbiditerelatedtoatransientreductionfrontfol- Klg04,werecollectedintheÇınarcıkbasinduringtheMar-
lowing the turbidite deposit (Çağatay et al., 2012). Finally, marascarpscruisein2002(Armijoetal.,2005),shortlyafter
these seismoturbidites are synchronous with distal fine- the 1999 M 7.4 Izmit earthquake (Fig. 1a, Table 2). They
w
graineddepositsintheadjacentWesternHighthatarerelated are3kmapartandliealongtheÇınarcikfaultsegmentbor-
to a thick suspension cloud above the turbidite flow deringthenorthernedgeofthebasin.CoreKlg03islocated
(McHugh et al., 2011; Drab et al., 2012). in the deepest part of the main Holocene depocenter
In the Çınarcık basin, the record of turbidites has not (1240m.b.s.l.;Cartonetal.,2007),1.6kmsouthofthemain
beenstudiedindetailyet,butSarıandÇağatay(2006)iden- faultstrand.Thesiteisonthemainpathofturbiditescoming
tified reworked deposits in sediment cores and inferred a from the northern shelf, but it can also be reached by turbi-
seismic trigger due to (1) the increase in different detrital ditesgeneratedontheCentralHighoronthesouthernslope
materialatthebaseoftheirevents,(2)theoccurrenceofshal- (Fig. 1c). Core Klg04 is located in a topographic berm be-
lowbenthic foraminifers, and(3)theexclusion ofanyother tweentwosplaysoftheÇınarcıksegmentnearthebaseofthe
possible triggering mechanism. 1000 m high northern slope in front of the Prince Islands
(Fig. 1c). It lies 300 m north of the main fault segment
and is 35 m higher than the Klg03 site (Fig. 1d). Because
Paleo-Environmental Changes Recorded in the
the Klg04 site is placed significantly above the basin floor,
Marmara Sea
it can be reached only by turbidites originating from the
Evidence for the simultaneous deposition of sediment northern shelf.
can be established in the Maramara Sea cores because Hol- In this article, we also used data from core Klg06,
ocenesedimentationdisplaysdistinctandimportantchanges. locatedontheWesternHigh,100kmawayfromtheÇınarcık
Forthelast4ka,mostofthesechangeshavebeenrelatedto basin (Fig. 1b). The core spans the last 7 ky and does not
anthropogenic disturbances (Mudie et al., 2002; Kazanci contain a record of coarse-grained turbidites like the ones
et al., 2004; Valsecchi et al., 2012). deposited in the basins of the Marmara Sea (Drab et al.,
Pollen studies (Mudie et al., 2002; Valsecchi et al., 2012). Core Klg06 is thus used to highlight global environ-
2012) documented two phases of forest clearance. The first mentalchangesthatoccurredintheMarmaraSeaandtopro-
phase occurred from 5 to 4 ky B.P. The second one started vide common time horizons in-between the Klg03, Klg04,
around 2.5 ka and marked the first appearance of sustained and Klg06 cores.
agriculture along the Marmara Sea coasts (Mudie et al., A number of sedimentological investigations were per-
2002,2007;Valsecchietal.,2012).Forestclearancewasas- formed to describe and characterize turbidites in the cores.
sociated with significant land degradation in the Marmara X-rayradiographsobtainedonthescopixsystematEnviron-
Sea catchments (Kazanci et al., 2004; Valsecchi et al., nements et Paloenvironnements Ocaniques et Continentaux
2012).Thesechangesinvegetationandlandusetriggeredan (EPOC) research group in the University of Bordeaux were
increase in sedimentary flux to the Marmara Sea (Walling, usedtoidentifyturbidites,similartomethodsusedbyBeck
2006)andresultedinaprogressiveincreaseinsedimentation etal.(2007)andDrabetal.(2012).Grainsizemeasurements
rateontheMarmarasouthernshelf(Kazancietal.,2004).In were performed on bulk sediment every centimeter on a
addition, about 2 ka ago, a global increase in grain size MalvernMastersizer2000tosupporttheidentificationoftur-
synchronous with a step increase in lead and titanium was bidites (Folk, 1968; Sperazza et al., 2004; Bertrand et al.,
describedintheMarmaraSeadeepbasins(Fig.2;Drabetal., 2008).Magneticsusceptibilitymeasurementswereobtained
2012). onsplitcoresusingaBartingtonMS2Eevery5mmatroom
Submarine Earthquake History of the Çınarcık Segment of the NAF in the Marmara Sea, Turkey 627
Figure 2. SummaryofmajorHolocenesedimentationchangesobservedincoreKlg06withx-rayfluorescence(XRF),grainsize,and
totalorganiccarboncontent.Agesobtainedfromdifferentstudies(Vidaletal.,2010;Drabetal.,2012;Valsecchietal.,2012;Drabetal.,
2015) are indicated on the left side of the log. The color version of this figure is available only in the electronic edition.
temperatureandhighlightbedsenrichedinmagnetite,which Thechronologyofthesedimentcoresisbasedon210Pb,
accompaniescoarsedetritalmaterialthatcancharacterizethe 137Cs, and 14C analyses and paleomagnetic measurements.
base of turbidites (Evans and Heller, 2003). XRF data were The 210Pb and 137Cs radionuclides were measured using a
acquiredusinganAvaatechXRFcorescannerandwereused semiplanar γ detector (University of Bordeaux 1) at EPOC
to describe geochemical and sedimentological processes (Schmidtetal.,2009).Paleomagneticmeasurements(secular
associated with earthquake-related deposits by comparing variationofthegeomagneticinclinationanddeclination)pro-
elements considered as detrital with more local ones, like vided independent time constraints. The natural remanent
calcium. Measurements were taken every 5 mm with radia- magnetization(NRM)wasmeasuredon1.5mlongU-channel
tionenergiesof10and30keVtoreachalargespectrumof samples cut from cores using a horizontal cryogenic magne-
elementscomprisingcalcium(Ca),Ti,manganese(Mn),and tometer 2G-enterprise at the paleomagnetic laboratory of the
Zr.Because theXRFdata needtobecomparedthroughand Institut de Physique du Globe de Paris. Measurements were
between thesediment cores regardlessof the absolutevalue performed every 2 cm. The NRM was progressively demag-
oftheconcentrations,westandardizedthedatatohaveazero netizedusinganalternatingfieldin11stepsuptoamaximum
meanandunitvariance.Wealsousedratiosofelementsthat field peak of 90 mTon Klg04. The characteristic remanent
provide the most easily interpretable signal of relative magnetization (ChRM) was then isolated using Zijderveld
changes in chemical composition and minimize the risk of diagrams and least-squares principal component analysis
drawing erroneous conclusions by enhancing the signal- (Kirschvink, 1980; Cogné, 2003). (Zijderveld diagrams are
to-noise ratio (Palike et al., 2001; Vlag et al., 2004; Bahr presentedinFig.A1).CoreKlg03wasalsoanalyzed,butonly
et al., 2005). twodemagnetizationstepswereappliedbecauseoftechnical
issues.
Acceleratormassspectrometryradiocarbondatingon24
Table 2
samples (benthic foraminifers, planktonic foraminifers, and
Location of Kullenberg Cores
mollusk shells) was carried out at Artemis LMC14 labora-
Latitude Longitude WaterDepth CoreDepth toryinLaboratoiredesSciencesduClimatetdel’Environne-
Core (°N) (°E) (m) (cm)
ment, Orsay, and at the Aeon laboratory (Table 3). Both
Klg03 40°47.98 28°59.55 1241 374
planktonic and benthic foraminifers were collected when
Klg04 40°48.60 29°00.73 1206 419
possible in hemipelagic sediments just above the tur-
Klg06 40°48.90 27°44.28 726 371
bidites. Mollusk shells were mostly extracted at the base
628 L. Drab, A. Hubert-Ferrari, S. Schmidt, P. Martinez, J. Carlut, and M. El Ouahabi
CorrectionC.)* Modeled 1894–E.1888C.E.–E.1713C.E.–1511C.E.E.–E.1449C.E. –E.1360C.E.–E.1352C.E.–E.1339C.E.–E.1334C.E. –E.1302C.E.–E.1226C.E.–E.1041C.E.–E.867C.E. –E.610C.E.–E.600C.E.–481E.C.E.–C.E.188B.C.E.–C.E.522B.C.E.–C.E.590B.C.E.–C.E.848B.C.E.–C.E.890B.C.E.–C.E.902B.C.E. –C.E.1362B.C.E.–C.E.1493B.C.E. continued()
Reservoir(B.C.E./B. 1769C.1550C.1364C.1342C. 1268C.1263C.1251C.1245C. 1185C.1058C.779C.607C. 429C.410C.136C.383B.771B.791B.1039B.1090B.1103B. 1552B.1720B.
CalibratedAgeswith400(cid:1)50ofyr Unmodeled –E.1805C.E.–E.1672C.E.N/A–E.1417C.E. N/A–E.1397C.E.–E.1309C.E.–E.1302C.E. –E.1283C.E.–E.1213C.E.N/AN/A –E.570C.E.–E.612C.E.N/A–C.E.197B.C.E.N/A–C.E.612B.C.E.–C.E.1087B.C.E.N/A–C.E.338B.C.E. –C.E.1387B.C.E.–C.E.1370B.C.E.
C.C. C. C.C.C. C.C. C.C. B. B.B. B. B.B.
98 0 060 29 97 0 08 0 59
06 1 777 52 63 6 20 9 64
54 2 100 09 22 5 94 4 67
e 11 1 111 1 1 3 11
or
C
5
Klg04 carbon†(yr) ±30±30 ±30±30±30 ±30±30±30±15±30±35 ±30±30±60 ±30 ±30±30 ±62±60±30±45±30±30±60
the RadioAge 10601140 148015801885 151515851595238016301740 453523702370 3045 33553750 412517360438015100491039754000
n
i
8
–E2E MassC(mg) 0.2670.91 0.8310.891.26 1.260.690.960.2590.710.23 0.690.860.061 0.56 0.90.43 0.91.10.710.70.770.068
s
nt
e3gEve 13δC‰() −5l9−0.6 −6.7−8.30.3 0.6−1.6−0.6−8.30.4−10.6 −1.7−1#N/A −3.6 −2.3−4.2 3.1−5.8−1.82−1#N/A
Tabl14CResultsConstrainin SampleType ‡Benthicforaminifer§Shell ‡Benthicforaminifer§Shell‡Benthicforaminifer ‡Benthicforaminifer§Shell§Shell‖Planktonicforaminifer‡Benthicforaminifer‡Benthicforaminifer §Shell§Shell‖Planktonicforaminifer §Shell §Shell§Shell Sapropel§Shell§Shell§Shell§Shell§Shell‖Planktonicforaminifer
of
y ee
ar Fr
m e-
Sum aTurbiditcale(cm) 1417284041 4848.54949.5 5256.56571 7878.58397105106110114115 154165
nS
i
h
pt
e
D
mpleDepthKlg04(cm) –10141728–40463845.588–5460100985911411468.5–7782–88.59291158158–04108.5203.5–30138.5130 –148152150162184197214351362
Sain 1 1
er
y
a
l
SampleName EventE1Klg04-17cmKlg04-28cmEventE2Klg04-38cmKlg04-45.5cmKlg03-88cmEventE3Klg03-100cmKlg03-98cmKlg04-59cmKlg03-114plccmKlg03-114cmKlg04-68.5cmEventE4EventE5Klg04-91cmKlg03-158cmKlg03-161cmEventE6Klg03-203.5cmEventE7Klg04-130cmKlg03-245cmEventE8TopofsapropelicKlg04-162Klg04-184cmKlg04-197cmKlg04-214cmKlg03-351cmKlg03-362cm
Submarine Earthquake History of the Çınarcık Segment of the NAF in the Marmara Sea, Turkey 629
ofturbidites.Sampleswereselectedinthefirst150cmofthe
two sediment cores to be able to relate recorded turbidites
e e
v h
B.C.E. andha witht wmiatyh hniosttobriecawleelalrtchoqnusatrkaeisnefdo.rAwgheicshwthereesecgalmibernatterduputsuirnegs
AgeswithReservoirCorrection0(cid:1)50yr(B.C.E./B.C.)* Modeled –B.C.E.2431B.C.E.2165 italicsarereworkedsamples maximumbounds),calibrated (f2Oa2aTotn00xradt01Chb03Gelsa)ehl.ylsoear3Bwblm)lBei,isgtce,.hwPea.drueptieshnlpeaaeatsnhtsMbkwsuutomoa(l1lrnoedi6indici0dfe,f1eteahs3rnaaepndtncldaatt3hln5siekbba0tmreroacnentpmstihileoce)irnscvfgootcayriufvrapoermvereatsfeihmfne(e(imicRfnsetoaeirfimislseml)uretsceshok1re4luleCsespthcaaeatmeglltldo.ees,
Calibrated40of Unmodeled –69B.C.E.2228 mpleswrittenin (minimumand STeudrbimideitnetsology, PhysiRcaelsuanltdsChemical Properties of
25 on.Sa level Visual inspection shows that all sediment cores have
CRadiocarbon†Age(yr) 4655±30 theturbiditehoriz 95.4%confidencecorrection). cmamcororeomnonstwtbtalsiyisnnaoieunrndnegitfwhcsohoeirtemmhllolpggsfosirrslaatieiygnnd-mFcsoleiiagfnzyseta.sl4mi(stihuaneoncadlcdsiouceg5asrey)ste.imodwHneiobntwyhotsfeafviernsweadtrpa,iirscxdaai-lnntyredaFyydtihegilampa.tmo3assgieianetdneariydde-
ued) Mass(mg) 0.45 cationof enatthereservoir ltgaeryraieyzreesdr(bis.iyel.ta,tlbuaayrsbeairld.ditTaehrsk)e.gTsrauanyrbdsiadlnaitdyeyedrleadpyioessrpialtasnydasraercueoslfulooalcllolaywtecedhdahbriaygcha-
ContinTable3( 13δCSampleDepthDepthinaTurbidite-Free‰()SampleNameinKlg04(cm)Scale(cm)SampleType ‖−§Klg04-268cm260194Shell2.7 “”Samplesareinstratigraphicorder,andtherowslabeledTurbiditesinboldshowthestratigraphiclootbeenincludedinthemodel.*UnmodeledandmodeledcalibratedagesaredeterminedusingOxcal(seeDataandResources),givMarine13curvethatincludesaglobalreservoirageof400yearswithoutthelocalcorrection(calledthe†1σUncertaintiesforconventionalradiocarbonagearegivenatthe(68.3%)confidencelevel.‡BulluminamarginataUvigerinaperegrineMelonisbarleeanumDatedbenthicforaminifersare,,and.§DatedmolluscshellsarefromthemolluscanclassMonoplacophora.‖GlobigerinabulloidesDatedplanktonicforaminifersare.13δ#Cnotmeasuredduetosamplesize. mpÇmswtmaKdcbmcdnlaetacTerayheodoslualtuoeiihanslilecaoasusitpmdraraelttgneoğptsoggjrehrsmkpimlilos0ygeeeateltnnrnl.ITheaiaser3lndtsnoattgoets(adaopucopsytiuot2jditfnumdyrnmsewcoorfpoliprfoo0i,.btcibemombnrfesisinuen0tpligcynrwaIitadhhvadtestKlduaeg7naonrartutayueonihnaihlrsi)ataseKtlrbtlrpoebssdetKiieggeieybl,ylnccleirtl.railitsa0enii,emsohlsggrendhhindong3intostps2i0rkeiiagciucfni5he0nneniditanntp3rv0eevohzrea.s0ii4aorulodebo,n1sbKeeenateyItK%l,mcw(reas2inirdlssbt∼gllebsioercnljs)hiigtietegauedhbdrsue.tovaosc5hKe0ieyrss0slotenranneefAeespnoe3-ctbl3ltctdsrbteggmgouaswhohtaillcm,(fhyaorudlyon0flaiimnloriasnbnlcaenilidepd4n)oattnaiteyanomophhqdeoiemfmlscrthitgxsrvcareeszuelu,sdheicpetiaa-meo(ieicnnerhesenallrssnrbilFlgdbiroatenannfaace,irtilaaieiitlsyiernegylytfodtoctgthtedssaaalieyAsheasnifyfa.seotbittdalciyiseeoatii.ilaa,tmi(ebToneinaeosuhn∼ymb3tdtslshsutddftglnhmBehsaaiiheeaaeb2Fotiyhnleegayiiwrrtyms,et,nwinnnhagt4sveeeacgtevbl43ertitCeesar0alamsrsaocpteaaK7,n)endrr%ayh.s,(lkxrs.-elt0uratutnFtleeaha4eanholihsrgnTtmetd2ronynisqnu.hoeacshi0gssdash–ywbedduicstmeefia,itn4so5irrcsi-nthiar5mle.sttdetiufrnkaoaekhoDs)rarcaa3lrsKy)meus.bo5eoefnmencs,aaenbs-Tam,intldhewdoctsnrstn4hgoo(shstgdrhosstessdh,eee0athihu3aoFibtecrdegt.yliml4aKioten0shcaolemienyicgnoBg.m,wmd%ianateklbemaapdv.targtaasten.aiorateseux4aeir0nndecebatlsIln5imcyrrrsi)lddydgnky3noeea------t;;.,
n
coreshows14erosive-baseturbidites,withthicknessesrang-
ing from 4 to 8 cm, and four nonerosive base turbidites
630 L. Drab, A. Hubert-Ferrari, S. Schmidt, P. Martinez, J. Carlut, and M. El Ouahabi
(a) (b)
%sand Ca/Ti Mn Zr MS
%sand Ca/Ti Zr MS
40
2
120 e
Core depth (cm) Turbidite 4 Laminations pth (cm) 50 Turbidit
e
129 d
e
0 4 8 12 -3 -1 1 3 or
C
% sand Zr (standardized) e 3
6 8 10 20 30 40 50 60 dit
Ca/Ti Magnetic Susceptibility (SI) urbi
60 T
0 4 8 -2 0 2 4 6 8
% sand Zr (standardized)
6 8 10 -1 0 1 2
Ca/Ti Mn (standardized)
10 20 30 40 50 60
Magnetic Susceptibility (SI)
Figure3. Typicalexamplesofturbidites:grainsizeandgeochemical(Ca=Ti,Mn,Zr,andmagneticsusceptibility)signatures.Turbidites
arecomposedofabasalsandlayer,anuppersiltlayerwithfrequentlaminations,andanupperlight-grayclayeylayer.(a)X-rayimagery,
grainsize,andgeochemicalprofilesofturbiditee4at120cmdepthinKlg03.(b)X-rayimagery,grainsize,andgeochemicalprofilesof
turbiditee2at45cmdepthinKlg04.Manganesetypicallyshowsapeakjustbelowturbidites.Thecolorversionofthisfigureisavailableonly
in the electronic edition.
(Fig.4).Twenty-threeturbiditesarerecordedinKlg04,with Theoriginofthemagneticdrophasbeenextensivelystudied
thicknesses ranging from 3 to 8 cm (Fig. 5). byDrab(2012)andDrabetal.(2015).Theoccurrenceofthe
verylowmagnetizationislinkedtothedepositionoforganic-
rich material forming a sapropelic layer (Cramp and O’Sul-
Correlation of Cores and Turbidites livan, 1999; Larrasoaña et al., 2003).
The cores Klg03 and Klg04 were correlated with the Inaddition,aglobalincreaseingrainsizeisidentifiedin
Klg06 reference core based on the occurrence of synchro- the cores and is linked with the deforestation and growth in
nous global changes in the sedimentation (Fig. 6). Among sedimentfluxobservedforthelast2ka(Kazancietal.,2004;
these changes, a sapropelic layer is clearly identified in Walling,2006; Valsecchietal.,2012).Finally,weusedXRF
Klg04 and Klg03 cores. Sapropelic layers are organic-rich data to identify other correlative changes in the Klg04 and
layers commonly found in the Mediterranean area (Rohling Klg03cores(Fig.6).First,theupperpartofthecoresshows
andHilgen,1991;CrampandO’Sullivan,1999;Larrasoaña an increase in Br, representing an increase in organic matter
et al., 2003) and in the Marmara Sea (Çağatay et al., 2000; (Ziegler et al., 2008; Drab et al., 2012). Second, both cores
Tolun et al., 2002; Vidal et al., 2010). The last referenced show a wide peak in Sr above the upper sapropelic layer.
sapropeliclayerwasidentifiedbyÇağatayetal.(2000)and Third,thetwocoreswerecorrelatedbasedonthevariationof
occurred between 4.7 and 3.2 ky in the Marmara Sea. We Ca=Ti ratio and Br content (Bahret al., 2005; Gracia et al.,
identifiedthelastsapropeliclayerinthecoresbyanincrease 2010). In the Marmara Sea, long-term regional variations in
in total organic carbon content (Drab, 2012; Drab et al., the Ca=Ti ratio are related to environmental changes, and
2015). The layer is mapped in Figure 6 and can be used Drab et al. (2012) have shown that the record for the
as an independent time constraint for the core chronology. Klg04 core can be linked to the Klg06 core in the Western
Paleomagnetic measurements obtained on the Klg03 High.TheCa=TicurveinKlg04isveryspikycomparedwith
and Klg04 cores also display important variations in the theKlg06one,whichcouldbelinkedtobasalerosionduring
magnetic properties. A drop of magnetization in the NRM turbidite emplacement. Figure 6 shows the correlation of
data is observed at 250 cm in Klg03 and at 80 cm in Klg03andKlg04cores,excludingthe coarseturbiditesfrom
Klg04(Fig.6)andcorrespondstothedissolutionofmagnet- the record. The XRF variations in Klg06 core are also dis-
itegrainsthroughtheprocessofdiagenesisinthesediment. played as a reference.