@article {Gracia2010,
	title = {{Holocene earthquake record offshore Portugal (SW Iberia): testing turbidite paleoseismology in a slow-convergence margin}},
	journal = {Quaternary Science Reviews},
	volume = {29},
	number = {9-10},
	year = {2010},
	month = {may},
	pages = {1156{\textendash}1172},
	abstract = {The SW margin of the Iberian Peninsula hosts the present-day boundary between the Eurasian and African Plates. Convergence (4-5 mm/yr) is accommodated through a wide deformation zone characterized by moderate magnitude seismic activity. This zone has also been the source of the most important seismic events in Western Europe, such as the 1755 Lisbon Earthquake and Tsunami and 1969 Horseshoe Earthquake. Despite efforts to identify active seismogenic structures in the Gulf of Cadiz in the last ten years, little is known about its paleoseismic history. The turbidite paleoseismology approach was applied for the first time in a low-rate convergent margin to determine the recurrence interval of large earthquake events that occurred in SW Iberia during the Holocene. Four sediment cores collected at strategically located sites offshore Portugal (i.e. Tagus Abyssal Plain, Infante Don Henrique Basin and Horseshoe Abyssal Plain) reveal that these deep-sea basins preserve a record of episodic deposition of turbidites. In the SW Iberian Margin excluding special climatic events, earthquakes are the most likely triggering mechanism for synchronous, widely-spaced distributed turbidites during the Holocene, when the sea level was relatively stable. Age correlation together with textural, mineralogical, physical properties and geochemical signatures of the new cores complemented by pre-existing multicores and gravity cores reveals a total of 7 widespread turbidite events for the Holocene. Precise dating of the most recent turbidite event (E1) based on 210Pb and 137Cs geochronology provides an age of AD 1971 {\textpm} 3. This age corresponds to a high-magnitude instrumental earthquake in the region: the 1969 Horseshoe Earthquake (Mw 8.0). Calibrated 14C ages of subsequent widespread turbidite events (E3 and E5) correlate with the dates of important historical earthquakes and paleotsunami deposits in the Gulf of Cadiz area, such as AD 1755 and 218 BC, respectively. If older synchronous events (E6, E8, and E10) with ages ranging from 4960-5510 yr BP to 8715-9015 yr BP are also taken into account, a great earthquake recurrence interval of about 1800 years is obtained for the Holocene. Our correlations suggest that the turbidite record may be considered as a proxy for paleoseismic activity in low-convergence rate margins, and a valuable complementary tool in earthquake and tsunami hazard assessment along the coasts of the Iberian Peninsula and North Africa. {\textcopyright} 2010 Elsevier Ltd. All rights reserved.},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2010.01.010},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77950629573\&partnerID=tZOtx3y1},
	author = {Gr{\'a}cia, Eul{\`a}lia and Vizcaino, Alexis and Escutia, Carlota and Asioli, Alessandra and Rod{\'e}s, {\'A}ngel and Pall{\`a}s, Raimon and Garcia-Orellana, Jordi and Lebreiro, Susana and Goldfinger, Chris}
}
@article {Pinero2007,
	title = {{Gas hydrate disturbance fabrics of southern Hydrate Ridge sediments (ODP Leg 204): Relationship with texture and physical properties}},
	journal = {Geo-Marine Letters},
	volume = {27},
	number = {2-4},
	year = {2007},
	pages = {279{\textendash}288},
	abstract = {Soupy and mousse-like fabrics are disturbance sedimentary features that result from the dissociation of gas hydrate, a process that releases water. During the core retrieval process, soupy and mousse-like fabrics are produced in the gas hydrate-bearing sediments due to changes in pressure and temperature conditions. Therefore, the identification of soupy and mousse-like fabrics can be used as a proxy for the presence of gas hydrate in addition to other evidence, such as pore water freshening or anomalously cool temperature. We present here grain-size results, mineralogical composition and magnetic susceptibility data of soupy and mousse-like samples from the southern Hydrate Ridge (Cascadia accretionary complex) acquired during Leg 204 of the Ocean Drilling Program. In order to study the relationship between sedimentary texture and the presence of gas hydrates, we have compared these results with the main textural and compositional data available from the same area. Most of the disturbed analyzed samples from the summit and the western flank of southern Hydrate Ridge show a mean grain size coarser than the average mean grain size of the hemipelagic samples from the same area. The depositional features of the sediments are not recognised due to disturbance. However, their granulometric statistical parameters and distribution curves, and magnetic susceptibility logs indicate that they correspond to a turbidite facies. These results suggest that gas hydrates in the southern Hydrate Ridge could form preferentially in coarser grain-size layers that could act as conduits feeding gas from below the BSR. Two samples from the uppermost metres near the seafloor at the summit of the southern Hydrate Ridge show a finer mean grain-size value than the average of hemipelagic samples. They were located where the highest amount of gas hydrates was detected, suggesting that in this area the availability of methane gas was high enough to generate gas hydrates, even within low-permeability layers. The mineralogical composition of the soupy and mousse-like sediments does not show any specific characteristic with respect to the other samples from the southern Hydrate Ridge. {\textcopyright} Springer-Verlag 2007.},
	issn = {0276-0460},
	doi = {10.1007/s00367-007-0077-z},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34250188050\&partnerID=tZOtx3y1},
	author = {Pi{\~n}ero, Elena and Gr{\'a}cia, Eul{\`a}lia and Mart{\'\i}nez-Ruiz, Francisca and Larrasoa{\~n}a, Juan Cruz and Vizcaino, Alexis and Ercilla, Gemma}
}
