@booklet {Harders2014,
	title = {{Characterization of Submarine Landslide Complexes Offshore Costa Rica: An Evolutionary Model Related to Seamount Subduction}},
	year = {2014},
	month = {dec},
	publisher = {Springer International Publishing},
	abstract = {Offshore Costa Rica large seamounts under-thrust the continental convergent margin causing slides of complex morphology. The large dimension of the structures has attracted previous investigations and their basic characteristics are known. However, no detailed mapping of their complex morphology has been reported. Here we present a detailed mapping of the failure-related structures and deposits. We use deep-towed sidescan sonar data, aided by multibeam bathymetry to analyze their geometry, geomorphologic character, backscatter intensity, and spatial distribution. Those observations are used to analyze the relationship between landslide characteristics and abundance, to the changes in the style of deformation caused by the subduction of seamounts to progressively greater depth under the margin.},
	isbn = {10.1007/978-3-319-00972-8\_34},
	doi = {10.1007/978-3-319-00972-8\_34 <http://dx.doi.org/10.1007/978-3-319-00972-8\_34>.},
	url = {http://oceanrep.geomar.de/22515/},
	author = {Harders, Rieka and Weinrebe, Wilhelm and Ranero, Cesar R.}
}
@inbook {Harders2012,
	title = {{An overview of the role of long-term tectonics and incoming plate structure on segmentation of submarine mass wasting phenomena along the Middle America Trench.}},
	booktitle = {Submarine Mass Movements and Their Consequences - 5th International Symposium},
	year = {2012},
	pages = {391{\textendash}402},
	publisher = {Springer Netherlands},
	organization = {Springer Netherlands},
	address = {Dordrecht},
	abstract = {We study mass wasting along the Middle America Trench (MAT), a subduction zone dominated by tectonic erosion, using a comprehensive data set of seafloor relief. We integrate previous studies of long- Term tectonic processes to analyze how they influence the evolution of the slope structure and precondition the continental slope for mass wasting. We have used the distribution of an inventory of 147 slope failure structures along the MAT to discuss their relation to subduction erosion. We interpret that preconditioning of the slope by long- Term tectonics, interacts in a shorter- Term scale with features on the under- Thrusting oceanic plate to modulate the abundance and types of mass wasting phenomena. The complex origin of the incoming oceanic plate has produced abrupt lateral changes in plate age, crustal thickness, relief, and response to bending deformation at the trench, leading to its partitioning into six segments. We found that the continental-slope failure style and abundance are partitioned into six segments that spatially match the ocean plate segments. {\textcopyright} Springer Science+Business Media B.V. 2012.},
	keywords = {Convergent margin, Subduction erosion, Submarine landslide},
	isbn = {978-94-007-2161-6},
	doi = {10.1007/978-94-007-2162-3},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84904112373\&partnerID=tZOtx3y1},
	author = {Harders, Rieka and Ranero, Cesar R. and Weinrebe, Wilhelm},
	editor = {Yamada, Yasuhiro and Kawamura, Kiichiro and Ikehara, Ken and Ogawa, Yujiro and Urgeles, Roger and Mosher, David and Chaytor, Jason and Strasser, Michael}
}
@article {Geersen2011,
	title = {{Active tectonics of the South Chilean marine fore arc (35{\textdegree}S-40{\textdegree}S)}},
	journal = {Tectonics},
	volume = {30},
	number = {3},
	year = {2011},
	month = {jun},
	pages = {n/a{\textendash}n/a},
	abstract = {The South Chilean marine fore arc (35{\textdegree}S-40{\textdegree}S) is separated into four tectonic segments, Concepci{\'o}n North, Concepci{\'o}n South, Nahuelbuta, and Tolten (from north to south). These are each characterized by their individual tectonic geomorphology and reflect different ways of mechanical and kinematic interaction of the convergent Nazca and South American plates. Splay faults that cut through continental framework rock are seismically imaged in both Concepci{\'o}n segments and the Tolten Segment. Additionally, the Concepci{\'o}n South Segment exhibits prominent upper plate normal faults. Normal faults apparently relate to uplift caused by sediment underthrusting at depth. This has led to oversteepening and gravitational collapse of the marine fore arc. There is also evidence for sediment underthrusting and basal accretion to the overriding plate in the Tolten Segment. There, uplift of the continental slope has created a landward inclined seafloor over a latitudinal distance of 50 km. In the Nahuelbuta Segment transpressive upper plate faults, aligned oblique to the direction of plate motion, control the seafloor morphology. Based on a unique acoustic data set including >90\% of bathymetric coverage of the continental slope we are able to reveal an along-strike heterogeneity of a complexly deformed marine fore arc which had escaped attention in previous studies that only considered the structure along transects normal to the plate margin. Copyright 2011 by the American Geophysical Union.},
	issn = {02787407},
	doi = {10.1029/2010TC002777},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79958808106\&partnerID=tZOtx3y1},
	author = {Geersen, Jacob and Behrmann, Jan H. and V{\"o}lker, David and Krastel, Sebastian and Ranero, Cesar R. and Diaz-Naveas, Juan and Weinrebe, Wilhelm}
}
@article {Harders2011,
	title = {{Submarine slope failures along the convergent continental margin of the Middle America Trench}},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {12},
	number = {6},
	year = {2011},
	month = {jun},
	pages = {n/a{\textendash}n/a},
	abstract = {We present the first comprehensive study of mass wasting processes in the continental slope of a convergent margin of a subduction zone where tectonic processes are dominated by subduction erosion. We have used multibeam bathymetry along \~{}1300 km of the Middle America Trench of the Central America Subduction Zone and deep-towed side-scan sonar data. We found abundant evidence of large-scale slope failures that were mostly previously unmapped. The features are classified into a variety of slope failure types, creating an inventory of 147 slope failure structures. Their type distribution and abundance define a segmentation of the continental slope in six sectors. The segmentation in slope stability processes does not appear to be related to slope preconditioning due to changes in physical properties of sediment, presence/absence of gas hydrates, or apparent changes in the hydrogeological system. The segmentation appears to be better explained by changes in slope preconditioning due to variations in tectonic processes. The region is an optimal setting to study how tectonic processes related to variations in intensity of subduction erosion and changes in relief of the underthrusting plate affect mass wasting processes of the continental slope. The largest slope failures occur offshore Costa Rica. There, subducting ridges and seamounts produce failures with up to hundreds of meters high headwalls, with detachment planes that penetrate deep into the continental margin, in some cases reaching the plate boundary. Offshore northern Costa Rica a smooth oceanic seafloor underthrusts the least disturbed continental slope. Offshore Nicaragua, the ocean plate is ornamented with smaller seamounts and horst and graben topography of variable intensity. Here mass wasting structures are numerous and comparatively smaller, but when combined, they affect a large part of the margin segment. Farther north, offshore El Salvador and Guatemala the downgoing plate has no large seamounts but well-defined horst and graben topography. Off El Salvador slope failure is least developed and mainly occurs in the uppermost continental slope at canyon walls. Off Guatemala mass wasting is abundant and possibly related to normal faulting across the slope. Collapse in the wake of subducting ocean plate topography is a likely failure trigger of slumps. Rapid oversteepening above subducting relief may trigger translational slides in the middle Nicaraguan upper Costa Rican slope. Earthquake shaking may be a trigger, but we interpret that slope failure rate is lower than recurrence time of large earthquakes in the region. Generally, our analysis indicates that the importance of mass wasting processes in the evolution of margins dominated by subduction erosion and its role in sediment dynamics may have been previously underestimated. Copyright 2011 by the American Geophysical Union.},
	keywords = {Convergent margin, landslides, slope failure, Subduction erosion, submarine mass wasting, tectonics},
	issn = {15252027},
	doi = {10.1029/2010GC003401},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79959701829\&partnerID=tZOtx3y1},
	author = {Harders, Rieka and Ranero, Cesar R. and Weinrebe, Wilhelm and Behrmann, Jan H.}
}
@article {Petersen2009,
	title = {{Fluid seepage and mound formation offshore Costa Rica revealed by deep-towed sidescan sonar and sub-bottom profiler data}},
	journal = {Marine Geology},
	volume = {266},
	number = {1-4},
	year = {2009},
	month = {oct},
	pages = {172{\textendash}181},
	abstract = {Our analysis of geoacoustic data from the Middle American margin provides an insight into the formation and evolution mechanisms of mound structures observed on the continental slope offshore Costa Rica. Based on high-resolution deep-towed sidescan sonar and sub-bottom profiler (SBP) data six different mound and fluid seepage structures at the Hongo mound field are characterized in detail. The Hongo mound field is located on the lower continental slope offshore Nicoya peninsula in the prolongation of the subducting Nicoya fracture zone. The mounds have oval to circular shapes with diameters of 500-1600 m and relief heights of 60-100 m. High backscatter anomalies near the mound summits indicate carbonate precipitation and focused fluid seepage activity within the last 10 ka. The data do not show evidence for mud extrusions and the structures were probably formed by a combination of carbonate precipitation and mud diapirism. Based on seismic stratigraphy analysis, mud diapirism is at least active since 42.5-57 ka and average vertical growth rates vary between 6-24 cm/ka. However, if diapirism represents the dominant mound evolution mechanism, mound heights of 80 m point to much older mound ages of 330-1330 ka. {\textcopyright} 2009 Elsevier B.V. All rights reserved.},
	keywords = {carbonate, deep-towed side-scan sonar, fluid seepage, mound, mud diapir, sub-bottom profiler},
	issn = {00253227},
	doi = {10.1016/j.margeo.2009.08.004},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-72049084256\&partnerID=tZOtx3y1},
	author = {Petersen, Carl J{\"o}rg and Klaucke, Ingo and Weinrebe, Wilhelm and Ranero, Cesar R.}
}
@article {Barckhausen2008,
	title = {{Birth of an intraoceanic spreading center}},
	journal = {Geology},
	volume = {36},
	number = {10},
	year = {2008},
	pages = {767},
	abstract = {The Cocos-Nazca spreading center is one of the few examples of the formation of a spreading center by splitting of oceanic lithosphere. It was created when the Farallon plate, broke up in the early Miocene following the collision of the Pacific-Farallon spreading center with the North American continent. Much of the ancient Farallon plate corresponding to the area of opening is lost to subduction beneath Central America and South America, but new data from the conjugate area on the Pacific plate allow the first detailed reconstruction of the break-up process. The opening began after chron 7 (25 Ma) at a location of focused crustal extension caused by overlapping spreading centers that had evolved in response to a slight reorientation of a Pacific-Farallon ridge segment. Beginning at chron 6B (22.7 Ma), eastward progressing seafloor spreading started along an axis that most likely migrated toward the region of weak lithosphere created by the Galapagos hotspot. By chron 6 (19.5 Ma), plate splitting from the spreading center to the trench was complete, allowing the fully detached Cocos and Nazca plates to move independently. This kinematic change resulted in a significant ridge jump of the newly established Pacific-Nazca spreading center, a change in plate motion direction of the Nazca plate by 20{\textdegree}clockwise, and a large increase in Pacific-Cocos plate velocity in the middle Miocene. {\textcopyright} 2008 The Geological Society of America.},
	keywords = {Central Pacific, Farallon breakup, Galapagos hotspot, Magnetic anomalies},
	issn = {0091-7613},
	doi = {10.1130/G25056A.1},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-54949104690\&partnerID=tZOtx3y1},
	author = {Barckhausen, Udo and Ranero, Cesar R. and Cande, Steven C. and Engels, Martin and Weinrebe, Wilhelm}
}
@article {Sahling2008,
	title = {{Fluid seepage at the continental margin offshore Costa Rica and southern Nicaragua}},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {9},
	number = {5},
	year = {2008},
	month = {may},
	pages = {n/a{\textendash}n/a},
	abstract = {A systematic search for methane-rich fluid seeps at the seafloor was conducted at the Pacific continental margin offshore southern Nicaragua and northern central Costa Rica, a convergent margin characterized by subduction erosion. More than 100 fluid seeps were discovered using a combination of multibeam bathymetry, side-scan sonar imagery, TV-sled observations, and sampling. This corresponds, on average, to a seep site every 4 km along the continental slope. In the northwestern part of the study area, subduction of oceanic crust formed at the East Pacific Rise is characterized by pervasive bending-induced faulting of the oceanic plate and a relatively uniform morphology of the overriding continental margin. Seepage at this part of the margin typically occurs at approximately cone-shaped mounds 50 - 100 m high and up to 1 km wide at the base. Over 60 such mounds were identified on the 240 km long margin segment. Some normal faults also host localized seepage. In contrast, in the southeast, the 220 km long margin segment overriding the oceanic crust formed at the Cocos-Nazca Spreading Centre has a comparatively more irregular morphology caused mainly by the subduction of ridges and seamounts sitting on the oceanic plate. Over 40 seeps were located on this part of the margin. This margin segment with irregular morphology exhibits diverse seep structures. Seeps are related to landslide scars, seamountsubduction related fractures, mounds, and faults. Several backscatter anomalies in side-scan images are without apparent relief and are probably related to carbonate precipitation. Detected fluid seeps are not evenly distributed across the margin but occur in a roughly margin parallel band centered 28 {\textpm} 7 km landward of the trench. This distribution suggests that seeps are possibly fed to fluids rising from the plate boundary along deep-penetrating faults through the upper plate. Copyrignt 2008 by the American Geophysical Union.},
	keywords = {Authigenic carbonate, Chemosynthetic community, Subduction erosion},
	issn = {15252027},
	doi = {10.1029/2008GC001978},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70350099584\&partnerID=tZOtx3y1},
	author = {Sahling, Heiko and Masson, Douglas G. and Ranero, Cesar R. and H{\"u}hnerbach, Veit and Weinrebe, Wilhelm and Klaucke, Ingo and B{\"u}rk, Dietmar and Br{\"u}ckmann, Warner and Suess, Erwin}
}
@article {Klaucke2008,
	title = {{Multifrequency geoacoustic imaging of fluid escape structures offshore Costa Rica: Implications for the quantification of seep processes}},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {9},
	number = {4},
	year = {2008},
	month = {apr},
	pages = {n/a{\textendash}n/a},
	abstract = {Quantification of fluid fluxes from cold seeps depends on accurate estimates of the spatial validity of flux measurements. These estimates are strongly influenced by the choice of geoacoustic mapping tools. Multibeam bathymetry, side-scan sonar, and Chirp subbottom profiler data of several mound-shaped cold seeps offshore central Costa Rica show great variety in morphology and structure although the features are only a few kilometers apart. Mound 11 (a 35 m high and 1000 m in diameter structure), situated in the SE of the study area, has an irregular morphology but a smooth surface on side-scan sonar data, while mound 12 (30 m high, 600 m across) is a cone of more regular outline but with a rough surface, and mound Grillo (5 m high, 500 m across) shows the same rough surface as mound 12 but without relief. Video observations and sediment cores indicate that the structures are formed by the precipitation of authigenic carbonates and indications for extensive mud extrusion are absent, except for one possible mudflow at mound 11. Different sonar frequencies result in variable estimates of the extent of these mounds with low frequencies suggesting much wider cold seeps, consequently overestimating fluid fluxes. The absence of mud volcanism compared to accretionary prisms where mud volcanism occurs is related to different tectonic styles: strong sediment overpressure and thrust faulting in typical accretionary prisms can generate mud volcanism, while subduction erosion and normal faulting (extension) of the overriding plate at the Costa Rican margin result in fluid venting driven by only slight fluid overpressures. Copyright 2008 by the American Geophysical Union.},
	keywords = {Cold seeps, Costa Rica, Side-scan sonar},
	issn = {15252027},
	doi = {10.1029/2007GC001708},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-71749104881\&partnerID=tZOtx3y1},
	author = {Klaucke, Ingo and Masson, Douglas G. and Petersen, C. J{\"o}rg and Weinrebe, Wilhelm and Ranero, Cesar R.}
}
