References of "Hubert, Aurelia"
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See detailSubmarine Paleo-earthquake record of the Cinarcik segment of the North Anatolian Fault in the Marmara Sea (Turkey)
Drab, Laureen; Hubert, Aurelia ULg; Carlut, Julie et al

in Bulletin Seismological Society of America (in press)

The submarine part of the North Anatolian Fault (NAF) in the Marmara Sea is a significant hazard for the city of Istanbul (Turkey). The use of paleoseismological data to provide an accurate seismic risk ... [more ▼]

The submarine part of the North Anatolian Fault (NAF) in the Marmara Sea is a significant hazard for the city of Istanbul (Turkey). The use of paleoseismological data to provide an accurate seismic risk assessment for the area is constrained by the fact that the NAF system is submarine near Istanbul; thus a history of paleoearthquakes can be inferred only by using sediment cores. Here a record of turbidites was obtained in two cores and used to reconstruct the earthquake history along a main branch of the NAF, the Cinarcik Segment. Kullenberg core Klg04 (4 m long) was collected during Marmarascarps mission from a berm north of the fault and a second core (Klg03, 3.5 m long) was positioned in the Cinarcik Basin, 3 km south of the fault. Sedimentary sequences in the two cores were correlated using variations in Ca/Ti ratio, which reflect the local aquatic productivity compared with more terrigenous input. The turbidites between the two cores were then classified to distinguish the synchronous ones from the other ones. Radionuclide measurements suggest that the most recent turbidite recorded in both cores was triggered by the M=7.3 1894 earthquake. We conclude that the turbidites are earthquake-generated, based on: 1) their distinctive sedimentological and geochemical signatures, previously described and applied in the Marmara Sea; 2) the correlation of turbidites between cores at berm and basin sites; 3) the match of the most recent turbidites with a 19th century historical earthquake; and 4) the elimination of others processes. Because of its specific geomorphological location, core Klg04 likely records only mass wasting events related to the rupture on the Cinarcik Segment. To date older turbidites, we used 14C and paleomagnetic data to build an OxCal age model with a local reservoir correction (ΔR) of 400±50 yr. The Cinarcik Segment is found to have ruptured in AD1894, AD1509, sometime in the 14th century, AD989, AD740 and in the 5th century and have a mean recurrence interval of rupture between 243 and 396 years. Following the age model obtained we finally used the earthquake record history of the Cinarcik Segment to infer the rupture history of adjacent segments of the North Anatolian Fault during six earthquake cycles over the past 1500 years. [less ▲]

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See detailLand erosion and associated evolution of clay minerals assemblages in Mediterranean region (Southern Turkey): Amik Lake
El Ouahabi, Meriam ULg; Hubert, Aurelia ULg; Lebeau, Helene et al

Poster (2015, July)

Under Mediterranean context, continuous human occupation is attested in the Amik Basin (southern Turkey) since 6000-7000 BC. The Basin also is crossed by The Dead Sea Fault (DSF), a major neotectonic ... [more ▼]

Under Mediterranean context, continuous human occupation is attested in the Amik Basin (southern Turkey) since 6000-7000 BC. The Basin also is crossed by The Dead Sea Fault (DSF), a major neotectonic structure in the Middle East extending from the Red Sea in the south to the East Anatolian Fault Zone in the north. The study focuses on the mineralogy and clay mineralogy record of the Amik Lake occupying the central part of the Basin. Our objective is to constrain major mineralogical and clay minerals evolution in the area over the last 4000 years and assess changes that would be related to the different land uses during the different Bronze, Roman, Ottoman and Modern civilizations. Sediments were collected at 1 to 2 cm intervals in core sediments up to a depth of 6 meters in the clay deposits. Geochemistry (XRF), mineralogy (XRD) and clay mineralogy are applied to study the sediment records. The age of the record is constrained combining radionuclide and radiocarbon dating. Chemical and mineralogical composition of sediments is quite diversified reflecting the significant geological variation of drainage basins. Abundant mixed-layer and partly disordered minerals characterize the different sedimentary levels recorded in those cores. Levels relatively rich in chlorite, illite and quartz are interpreted as corresponding to relatively dry periods, while more humid periods lead to more intensive weathering and consequently to the dominance of clay minerals more advanced in the relative stability scale, such as kaolinite. Smectite is taken to indicate a climate with contrasting seasons and a pronounced dry season. The sedimentary record clearly shows two periods indicating strong soil erosion in the Lake catchment. The most recent erosion phase is modern. The oldest one would have started during the late Bronze period and lasted until the late Roman Period. The first and older period is attributed to a strong aggradation linked to major increase in erosion. Our study shows that this episode has specific characteristics: mixed-layer clay mineral, high percent in Ni, Cr and Mg coupled with significant amount of organic matter of terrestrial origin. Ni and Mg most probably come from the Amanos Mountains an ophiolitic belt indicating an intensive upland cultivation and possible exploitation of its mineral resource. The second period is attributed to the modern period. The signature of the increase in erosion is different, because most of the soil cover has already been eroded. Only a patchy thin and unmature soil cover exists since the Late Roman time. Erosion is associated with a marked increase of smectite-illite interstratified clay, goethite and hematite found in deep soil horizons. Moreover, a marked increase in Cr is showed and is probably related to an enhanced exploitation of its mineral resource and to a renew land exploitation of the Amanos Mountain Range. [less ▲]

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See detailLate Holocene history of the Fuji Five Lakes (Japan)
Lamair, Laura ULg; Hubert, Aurelia ULg; Boes, Evelien et al

Conference (2015, July)

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See detailInfluence of bottom currents on the sedimentary processes at the western tip of the Gulf of Corinth, Greece
Beckers, Arnaud ULg; Beck, Christian; Hubert, Aurelia ULg et al

in Marine Geology (2015)

We investigated the sedimentary processes that were active during the Holocene in the Gulf of Corinth, using high-resolution seismic reflection profiles and gravity cores. Seismic reflection data clearly ... [more ▼]

We investigated the sedimentary processes that were active during the Holocene in the Gulf of Corinth, using high-resolution seismic reflection profiles and gravity cores. Seismic reflection data clearly show the presence of shallow-water sediment drifts at the western end of the Gulf, close to the Rion Sill that links the gulf to the Ionian Sea. Short cores indicate that drifts are composed of homogenous bioturbated mud in their upper part. The drift deposits flank a wide central area where the sea floor is eroded and where pre-Holocene deposits locally outcrop. The sea floor morphology in this area is marked by furrows oriented in different directions and by a depression attributed to the action of bottom-currents. The magnetic fabric of sediment samples from the drift, shelves, sub-basins and from the basin floor show a significant anisotropy and a similar orientation of Kmax axes along core. The largest anisotropy (P = 1.043 ± 0.007) is observed in the drift and is interpreted as resulting from the action of bottom currents. The similar orientation of Kmax axes in the other cores, collected from areas East of the drifts, suggests that bottom currents also affect sediment deposition in the rest of the study area, even if seismic profiles and core analyses demonstrate that gravitational processes such as submarine landslides and turbidity currents exert the main control on sediment transport and deposition. Average Kmax axes for four cores were reoriented using the declination of the characteristic remanent magnetization. Kmax axes show variable orientations relatively to the slope of the sea floor, between along-slope and roughly parallel to the contour lines. [less ▲]

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See detailSedimentary impacts of recent moderate earthquakes in different settings in the Western Gulf of Corinth, Greece
Beckers, Arnaud ULg; Mortier, Clément; Beck, Christian et al

Poster (2015, April 21)

11 short gravity cores retrieved in the Western Gulf of Corinth, Greece, allowed identifying event deposits whose age ranges were compared to an updated earthquakes catalogue for the area. 210Pb-derived ... [more ▼]

11 short gravity cores retrieved in the Western Gulf of Corinth, Greece, allowed identifying event deposits whose age ranges were compared to an updated earthquakes catalogue for the area. 210Pb-derived age-depth curves show that the majority of the event deposits may have been triggered by earthquakes. These results show that moderate earthquakes (Mw ~6.0-6.5) may significantly impact different marine settings, from shallow shelves (70-100 m deep) to the basin floor (330 m deep). The deepest coring sites show the best possible record, but one major earthquake is missing and the age of one event deposit does not fit with any known earthquake. More cores are needed to check the spatial extent of each deposit and to validate the absence of record of some earthquakes, like the 1995 Aigion earthquake. [less ▲]

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See detailBasement depth and sedimentary infill from deep seismic reflection data at the western tip of the offshore Corinth Rift
Beckers, Arnaud ULg; Tripsanas, Efthymios; Hubert, Aurelia ULg et al

Conference (2015, April 17)

The Corinth rift is a young continental rift located in central Greece. The active part of the rift forms an E-W striking depression – the Gulf of Corinth – that is the deepest in its central part ... [more ▼]

The Corinth rift is a young continental rift located in central Greece. The active part of the rift forms an E-W striking depression – the Gulf of Corinth – that is the deepest in its central part. Extensive seismic surveys have imaged the basin's basement and allowed to estimate the total extension across most of the Gulf except its western tip. Extension is high in the central part and decreases westward and eastward, as reflected in the present-day bathymetry. Two decades of GPS measurements have shown that the extension rate increases westwards from ~5 to 10-15 mm yr-1, but this is not consistent with the long term pattern. However, no data allowed so far to estimate the basement depth at the western tip of the Gulf, where the geodetic extension rate is the largest. Such data would allow to check the apparent inconsistency between the present rate and the long-term estimates of crustal extension. We present here an unpublished multichannel seismic line dating from 1979 and crossing the western tip of the Gulf of Corinth. The line is 22 km long and strikes WNW-ESE, from the Mornos delta to the West-Channel fault. A Maxipulse source has been used, allowing to image the basement below the synrift sedimentary infill. To the east, a ~1.6 km deep basin is imaged between the southern margin of the Gulf and an inactive south-dipping fault located between the Aigion and the Trizonia faults. The sedimentary infill consists in an alternation between basin-focused bodies made of incoherent reflections and more extensive high-amplitude reflectors. Attributing this alternation to eustatic variations give an age of 300-350 ka to the oldest well imaged deposits. Northwest of the Trizonia fault, the basement is imaged at shallower depth, i.e. ~450 m. The western tip of the seismic line reaches the Mornos delta, close to the northern shoreline. There, the depth to the basement is larger, reaching ~1.2 km. The infill is made of 3 units : on the basement lies a thin unit of incoherent reflections that may corresponds to coarse-grained fluvial deposits. A second unit of parallel, high-amplitude, low-frequency reflections could represent deeper-water deposits. The last seismic unit represents the Mornos delta coarse-grained deposits, from 0 to ~0.7 km deep. The depth of the basement deduced from this seismic line at the western tip of the Gulf of Corinth (1.2-1.6 km) is shallower than the one in the central part of the Gulf (2.5-3 km). This reinforce the inconsistency between long-term and short-term rates of extension in the Corinth Rift, which may be explained by assuming that the Western Corinth Rift initiated much later than the Central Rift. These data also allow to constrain the total displacement on the N-dipping Psathopyrgos fault, one of the major, normal, basin-bounding faults at the western tip of the Rift. The total offset would reach 2.1-2.3 km and the uplift/subsidence ratio would be ~1:1.7, implying a slip rate of 2.2-2.5 mm yr-1 based on footwall uplift rate data. [less ▲]

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See detailInvestigation of the Five Fuji Lakes and their potential of recording paleoearthquakes
Lamair, Laura ULg; Hubert, Aurelia ULg; Boes, Evelien et al

Conference (2015, March 04)

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See detailCharacterization of building materials from the aqueduct of Antioch-on-the-Orontes (Turkey)
Benjelloun, Yacine; de Sigoyer, Julia; Carlut, Julia et al

in Comptes Rendus Geoscience (2015)

The Roman aqueduct of Antioch-on-the-Orontes (Turkey), a city located near the junction between the active Dead Sea fault and the East Anatolian fault, has been damaged several times due to historical ... [more ▼]

The Roman aqueduct of Antioch-on-the-Orontes (Turkey), a city located near the junction between the active Dead Sea fault and the East Anatolian fault, has been damaged several times due to historical earthquakes, as mentioned in ancient texts. The traces of repairs are studied in order to identify their potential seismic origin. The deformations of the structure were characterised thanks to a LIDAR scan. Several bricks were sampled on different parts of the city’s aqueducts, on the original structure and on repaired parts. The bricks were characterized through a petrological approach. 14C and archaeomagnetism were tested on the bricks in order to constrain the age of their production. The synthesis of all the data showed a local origin for the bricks, and led to the identification of several manufacturing techniques and several types of production, thus, confirming the potentiality of this approach to date and characterise post-seismic repairs. [less ▲]

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See detailPatterns of Quaternary uplift of the Corinth rift southern border (N Peloponnese, Greece) revealed by fluvial landscape morphometry
Demoulin, Alain ULg; Beckers, Arnaud ULg; Hubert, Aurelia ULg

in Geomorphology (2015), 246

The Rift of Corinth is a world-class example of young active rifting and, as such, is an ideal natural laboratory of continental extension. However, though much investigated for two decades, several ... [more ▼]

The Rift of Corinth is a world-class example of young active rifting and, as such, is an ideal natural laboratory of continental extension. However, though much investigated for two decades, several aspects of the mechanisms at work are still poorly understood. The aim of this paper is a detailed morphometric study of the fluvial landscape response to the tectonic uplift of the rift southern shoulder in order to reconstruct the rift's Quaternary evolution, with special attention to timing, location, and intensity of uplift episodes. Based on the use of a large set of catchment and long profile metrics complemented by the newR/SR integrative approach of the regional drainage network, we identified three distinct episodes of uplift of the northern Peloponnese coastal tract, of which the intermediate one, dated around 0.35–0.4 Ma, is only recorded in the topography of the central part of the rift shoulder, and the youngest one appears to have propagated from east to west over the last 10–20 ka. While net uplift remained minimum in the eastern part of the study area during the whole Quaternary, it shows a clear maximumin the central part of the rift shoulder since 0.4 Ma and an eastward shift of this maximumin recent times. Maximum uplift rates calculated from the morphometric data are of N1.05 and 2–5 mmyear−1 for, the mid-Middle Pleistocene and Holocene uplift episodes, respectively. The morphometric evidence reveals an onshore uplift history remarkably consistent with the rift evolution reconstructed from other data sets. In the long term, it shows a stable pattern of maximum activity in the central part of the rift, confirming previous conclusions about the absence of rift propagation. In the short term, it sheds light on a possible E–Wmigration of the zone of recent uplift, suggesting that in the near future fault activity and seismic hazard might concentrate in the Heliki–Aegion area, at the western tip of this uplift wave. [less ▲]

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See detailPaleomagnetic and geochemical record from cores from the Sea of Marmara, Turkey: Age constraints and implications of sapropelic deposition on early diagenesis
Drab, Laureen; Carlut, Julie; Hubert, Aurelia ULg et al

in Marine Geology (2015), 360

We present results of a multi-proxy analysis of two sediment cores from the Marmara Sea. The cores were ana- lyzed using paleomagnetic and geochemical measurements. Two sapropels are documented in the ... [more ▼]

We present results of a multi-proxy analysis of two sediment cores from the Marmara Sea. The cores were ana- lyzed using paleomagnetic and geochemical measurements. Two sapropels are documented in the last 11 kyr and are recorded in several locations across the Marmara Sea. These two sapropels have contrasting magnetic prop- erties. The magnetic record is affected by intense early diagenesis; the most recent upper sapropelic layer has low remanence and susceptibility values. A record of paleomagnetic inclinations could still be isolated above the dia- genesis front and is compared with secular variation models. The lower sapropel is identified in the deep part of the oldest studied core (Klg07) and has distinct magnetic properties characterized by high remanence and sus- ceptibility values. Using the magnetic properties it is possible to constrain bottom water ventilation and recon- nection episodes between the Marmara Sea and the Black Sea following the sea level rise during the last glacial to inter-glacial transition. [less ▲]

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See detailActive faulting at the western tip of the Gulf of Corinth, Greece, from high-resolution seismic data
Beckers, Arnaud ULg; Hubert, Aurelia ULg; Beck, Christian et al

in Marine Geology (2015)

The Gulf of Corinth is one of the fastest-spreading intra-continental rifts on Earth. GPS data indicate that the rift is currently opening in a NNE-SSW direction, with a rate of extension reaching up to ... [more ▼]

The Gulf of Corinth is one of the fastest-spreading intra-continental rifts on Earth. GPS data indicate that the rift is currently opening in a NNE-SSW direction, with a rate of extension reaching up to 16 mm yr-1 in its westernmost part. Although the rest of the offshore rift has been well studied, the western tip of the rift is still poorly explored. We present an accurate map of submarine faults in this area based on two high-resolution seismic reflection surveys (single channel sparker). In the eastern part of the studied area, the sedimentary infill is affected by the known North Eratini, South Eratini and West Channel faults. Further to the west, the seafloor is mostly flat, and is bounded to the north by the normal, south-dipping, Trizonia fault. To the north, the shallower part of the Gulf shows to the east a diffuse pattern of normal and strike-slip deformation which is replaced to the west by a 7.5 km long SE striking strike-slip fault zone, called the Managouli fault zone. To the westernmost tip of the Gulf, in the Nafpaktos Basin, two fault sets with different strikes are encountered; the one with aNE-SW strike exhibits a clear strike-slip component. The western tip of the Gulf of Corinth is the only part of the Corinth Rift where convincing evidence for strike-slip movement has been found. This fault pattern is likely related to the complex deformation occurring at the diffuse junction at the western tip of the Rift between three crustal blocks: Continental Greece, Peloponnese, and the Ionian Island-Akarnia block. [less ▲]

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See detailEvidence for Holocene bottom-currents erosion in the Western Gulf of Corinth, Greece
Beckers, Arnaud ULg; Beck, Christian; Hubert, Aurelia ULg

Poster (2014, September 10)

The Gulf of Corinth, Greece, is connected to the Ionian Sea through a 62 m deep sill. Strong tidal currents have been measured above this sill, what could potentially induce bottom-current erosion in the ... [more ▼]

The Gulf of Corinth, Greece, is connected to the Ionian Sea through a 62 m deep sill. Strong tidal currents have been measured above this sill, what could potentially induce bottom-current erosion in the Gulf. Seismic reflexion data allowed us to identify this present-day expected seafloor erosion in a wide area, as well as erosional unconformities and a wide channel between 100 and 300 m below sea level. These features highlight the possible occurrence of strong bottom-currents since the last sea level rise. [less ▲]

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