present day kinematics of the mediterranean a comprehensive overview of gps results i combine recently published gps results to derive a geodetic horizontal velocity field consistent at the scale of the mediterranean and the surrounding alpine belts the velocity field is then used to discuss the boundary conditions around each major deforming area in the mediterranean to describe the main patterns of motion and deformation to critically review the existing kinematics models and to finally point out the main unresolved kinematics questions strain rate in europe north of the alpines belt is dominated by the signature of the glacial isostatic adjustment and tectonic strain remains below the current accuracy of gps results in the western mediterranean deformation is restricted to the betics the alboran and the morrocan rif with west to southwestward motion with respect to iberia which is part of stable europe shortening consistent with the relative nubia eurasia plate motion is found throughout the maghrebides but the distribution of deformation in northern africa remains largely unknown the central mediterranean is dominated by the counter clockwise rotation of the adriatic the junction between the southern adriatic domain and nubia has yet to be firmly established the deformation over a wide area east of the maghrebides in tunisia and the gulf of sirte in libya still remains to be quantified in the eastern mediterranean the velocity field is dominated by a general anti clockwise rotation and a general trend towards the hellenic trench with velocity magnitude increasing with decreasing distances from the trench this trend is observed not only in the aegean and anatolia but also in the southern balkans geodetic results emphasize that the convergence of the nubia and arabia plates towards eurasia directly controls the deformation across only very few segments along the plate boundary zone additional processes are therefore required to explain the observed velocity field and deformation pattern

regional scale co seismic landslide assessment using limit equilibrium analysis abstract traditionally regional assessment of seismic slope stability has been done using the infinite slope rigid sliding block analysis a major disadvantage of this approach is the resulting overestimation of the critical acceleration of the slope due to the underlying assumption of a predefined slope failure plane and consequently the underestimation of hazard areas prone to sliding in this paper we present a modified approach for assessing seismic slope instabilities using a model based on limit equilibrium analysis and circular slip surfaces with no restriction to any predefined slope failure plane for this purpose we conduct a parametric study to identify the relationship between the critical acceleration of the slope the slope angle and the slope shear strength parameters we model typical slopes in the rocscience software slide using bishop s limit equilibrium method to identify the critical accelerations that corresponds to a failure plane with factor of safety equal to one the critical accelerations were plotted against the variables in the parametric study and the best fit equations were obtained the proposed approach was developed for global application but it was tested using the well documented co seismic landslide database of the 1994 northridge ca earthquake the predicted sliding areas were compared to the inventory of landslides that were triggered in the val verde region in los angeles by the earthquake qualitative and quantitative assessments of the proposed model clearly show its advantages in predicting potential sliding areas

extraordinary distance limits of landslides triggered by the 2011 mineral virginia earthquake the 23 august 2011 mineral virginia earthquake m w 5 8 was the largest to strike the eastern u s since 1897 and was felt over an extraordinarily large area although no large landslides occurred the shaking did trigger many rock and soil falls from steep river banks and natural cliffs in the epicentral area and from steep road cuts along and northwest of the blue ridge parkway we mapped the occurrence of rock falls to determine distance limits that could be compared with those from other documented earthquakes studies of previous earthquakes indicated a maximum epicentral distance limit for landsliding of 60 km for an m 5 8 earthquake the maximum distance limit for the 2011 earthquake was 245 km the largest exceedance of the historical limit ever recorded likewise the previous maximum area affected by landslides for this magnitude was 1500 km2 the area affected by landslides in the 2011 earthquake was 33 400 km2 these observations provide physical evidence that attenuation of strong shaking for eastern u s earthquakes is significantly lower than for plate boundary earthquakes also distance limits parallel to the regional structural trend are greater than those that transect the structure which suggests anisotropic attenuation related to the regional geologic structure peak ground acceleration pga at the landslide distance limits is estimated to have been about 0 02 0 04 g

earthquake induced ground failures in italy abstract the national catalog of ground failures induced by strong earthquakes in italy cedit is described the catalog holds data on ground failures triggered by the earthquakes that occurred in italy in the last millennium and which had a nominal epicentral intensity equal to or greater than viii in the mercalli cancani sieberg mcs intensity scale the ground effects reported in the catalog are the following landslides fractures liquefaction surface faulting and topographic changes of the ground level subsidence settlements tilting and so on each effect is described in terms of seismological parameters of the triggering earthquake site coordinates and administrative code lithology and kinematic type of the ground failure the catalog represents a tool to assess the susceptibility of geologic materials to ground shaking and to validate predictive models of seismically induced ground displacements scenarios of earthquake induced geologic risks in the context of this study a simple statistical analysis of the database yielded useful relations between the parameters of the triggering earthquakes and the related effects

early holocene deglaciation of the eastern coast of hudson bay abstract the final stage of deglaciation of hudson bay was a major holocene catastrophic event marked by the drainage of lake agassiz ojibway at 8 47 ka cal bp and the rapid collapse of the laurentide ice sheet previous work undertaken in the nastapoka river area eastern hudson bay demonstrated that during the relative sea level highstand that shortly followed the drainage of the lake the western margin of the quebec labrador ice sector rapidly retreated eastward to reach a stillstand position in a coastal hill range in this study an analysis of landsat 7tm images has allowed a mapping of large scale glacial landforms outwash deposits eskers flutings and de geer and rogen moraines between kuujjuaraapik se hudson bay and puvirnituq ne hudson bay the key results from this mapping are i ice contact outwash deposits mapped along the entire arc shaped coastline of the eastern hudson bay outline a major ice stillstand phase in the coastal hills that extended at least from kuujjuaraapik to inukjuak the presence of these hills allowed a stabilisation of the ice margin that led to the accumulation of thick and extensive ice contact submarine fans ii the position of these deposits on the down ice side west of large sets of flutings indicates an important phase of sediment delivery by a rapid ice flow phase toward a marine based ice margin iii a second system of outwash deposits observed farther inland indicates a subsequent phase of stabilisation of the ice margin during its retreat toward central quebec labrador

burial rates of organic matter along the eastern canadian margin and stable isotope constraints on its origin and diagenetic evolution abstract organic carbon oc and nitrogen n contents and 13 c and 15 n values in total organic matter om were measured in sub surface sediments 0 30 cm sub bottom from 21 cores raised from the laurentian channel of the gulf of st lawrence and the labrador sea to document om fluxes and storage along the eastern canadian margin storage rates as high as 2 5 g m 2 yr 1 for oc and 0 2 g m 2 yr 1 for n are observed in the laurentian channel suggesting that the shelf plays a significant role in terms of om storage from 1 to 2 of the primary production based on the isotopic composition of the essentially marine om of the labrador sea 13 c v pdb 21 9 0 4 15 n air 7 6 0 6 n 12 there is no isotopic evidence for a significant relative input of terrestrial om along the laurentian channel 13 c v pdb 21 9 0 4 15 n air 8 0 0 9 n 10 either due to high relative fluxes of marine om and or to the trapping of continental om in the estuary and upstream high storage rates of om are also observed on the continental rise of the labrador sea as high as 1 1 g c m 2 yr 1 and 0 09 g n m 2 yr 1 they contrast with one order of magnitude lower rates on the slope due to low sedimentation rates sr and sediment winnowing by the western boundary undercurrent wbuc reduced early diagenetic alteration of om is observed particularly in the laurentian channel it results in discrete i losses of oc and n ii shifts in c n ratios suggesting preferential removal of n bearing om also highlighted by losses in total hydrolysable amino acids haa in the labrador sea slope records due to low sr om concentration changes linked to long term temporal variations may superimpose on these diagenetic trends and some influence of the wbuc is noticeable

stable carbon and nitrogen isotopes as indicators for organic matter sources in the kara sea abstract stable carbon and nitrogen isotope ratios 13c 15n are frequently used to decipher organic matter sources and transformation processes here we present stable isotope data of suspended matter and sediments from the ob and yenisei estuaries and the kara sea arctic ocean in order to figure out how they are influenced by seasonal and interannual changes in river run off ice coverage and biological activity our study shows a progressive increase of stable carbon and nitrogen isotopic ratios in offshore direction and a positive correlation of salinity with 13c differences among the correlation of individual annual suspended matter data sets reveal a multitude of processes modulating 13c ratios such as sporadic plankton blooms variations in riverine end members and annual river run off despite this variability the correlation of salinity with 13c of suspended matter from the surface water is very similar to that of surface sediments with the average salinity of the ice free period however sediments show a shift to higher 13c values by about 2 2 since sinking particles in deep water are similar to sedimentary 13c ratios the correlation of salinity with 13c of sediments has been taken to reconstruct the paleosalinity of a sediment core off the yenisei river mouth since 10 000 yr bp

characterization of siberian arctic coastal sediments implications for terrestrial organic carbon export surface sediments were collected during the 2000 transarctic expedition along the siberian arctic coastline including the ob yenisey khatanga lena and indigirka estuaries sediments were chara

seismically induced landslides by a low magnitude earthquake the mw 4 7 ossa de montiel event central spain this work has been funded by spanish ministry of economy and competitiveness research project cgl2011 30153 c02 02 and by the research groups rnm 374 junta de andalucia tectac ucm 910368 and vigrob 184 universidad de alicante mr loffredo acknowledges funding of the universita di roma la sapienza post graduate grant concorso a n 480 area cun 04

climate change and recent sedimentation in nastapoka sound eastern coast of hudson bay in an attempt to determine to what extent the impact of recent climate changes that occurred east of hudson bay including important reduction of areas in permafrost had on the coastal marine environment a series of shallow cores were extracted from the seabed off the mouth of the sheldrake river in nastapoka sound a total of 25 cores were taken in april 2009 from the ice cover a preliminary seafloor map was first done to help in the selection of the coring sites nastapoka sound has a complex subaqueous relief formed of asymmetric ridges and deep basins after preliminary sedimentological analyses six of the cores were selected for physical and chronological analyses 14c 210pb and 137cs dating among them three were selected for elemental c n oc tn and isotopic 13c 15n analyses to identify sedimentary organic matter sources sedimentation processes are complex and are primarily driven by bottom currents this is confirmed by the absence of a clay fraction in several cores some erosi

laboratory simulation of exchange through fram strait laboratory experiments and theory were conducted to observe the flow patterns and transport in both buoyancy driven and wind driven rotating fluids in lock exchange experiments water with one density flows into a second basin after a sliding gate is removed water of a second density flows back into the first basin the size and location of the currents for various values of density difference rotation rate and assorted sidewall geometries was recorded volume flux of the fluid was also measured and compared with a theory for lock exchange flow of a rotating fluid in a separate group of experiments with a passive upper layer easterly winds like those in the arctic ocean drive the upper level water into the arctic ocean and therefore oppose the buoyant exchange westerly winds would drive the water out of the arctic ocean this indicates that the exchange between the arctic ocean and the greenland norwegian sea is likely to be driven by buoyancy rather than by driven by wind crude estimates of the volumetric and fresh water exchange rate from the lock exchange formulas are compared with observed ocean fluxes and approximate agreement is found

attenuation of intensity with epicentral distance in the iberian peninsula we have classified the attenuation of the medveded sponheuer and karnik msk intensity into five types each as a function of the epicentral intensity i o based on the mean radii of 254 isoseismal maps mainly historical earthquakes in the iberian peninsula geographically representing each earthquake with its corresponding attenuation tendency it can be seen that those with low attenuation lie west of the peninsula and those with high attenuation in the south and east this regionalization seems to be due as much to the seismotectonic characteristics different crustal types and size of the earthquakes as to the different construction types in each region these attenuation values are similar to those of southern europe but much higher than those found in the united states from the point of view of seismic hazard evaluation these laws represent an improvement with regard to those used so far we have extended previous attenuation studies to the whole of the iberian peninsula and in some points differences of attenuation assignment of almost two degrees of intensity have been corrected

can low magnitude earthquakes act as a triggering factor for landslide activity examples from the western carpathian mts poland abstract there are numerous examples of the impact of strong earthquakes on landslide activity there is however very little information about the ability of low magnitude earthquakes m

recent dramatic thinning of largest west antarctic ice stream triggered by oceans a growing body of observational data suggests that pine island glacier pig is changing on decadal or shorter timescales these changes may have far reaching consequences for the future of the west antarctic ice sheet wais and global sea levels because of pig s role as the ice sheet s primary drainage portal we test the hypothesis that these changes are triggered by the adjoining ocean specifically we employ an advanced numerical ice flow model to simulate the effects of perturbations at the grounding line on pig s dynamics the speed at which these changes are propagated upstream implies a tight coupling between ice sheet interior and surrounding ocean

a 210pb sediment budget and granulometric record of sediment fluxes in a subarctic deltaic system the great whale river canada abstract to elucidate how modern river discharge conditions of the great whale river gwr are represented in the marine sedimentary record eight box and gravity cores were examined in terms of 210 pb and 137 cs radiochemistry granulometry and physical sedimentary structures these data were analyzed to provide insights into sedimentary processes and patterns at the study site sediment accumulation in the study area appears to be a relatively steady process over time scales of 50 100 yr allowing biological activity to overprint the primary depositional fabric subtle differences between 137 cs and 210 pb sediment accumulation rates sars suggest an offshore shift in the locus of fine sediment deposition during the past 150 yr which may be a result of ongoing climatic warming leading to decreasing sea ice coverage and a more energetic marine environment under present day conditions 23 40 000 t yr of the discharged sediment appear to accumulate in a 25 km 2 area off the river mouth the remaining 77 136 000 t yr are either deposited further offshore possibly along the northeastern shore as a result of hudson bay s counterclockwise circulation or dispersed into the hudson bay system grain diameter frequency analyses suggest that environmental processes controlling sediment transport and deposition vary over decadal time scales although we cannot define an exact cause for this pattern these shifts may be related to variations in river discharge wave climate possibly due to windier conditions or less sea ice dampening bioturbation or a combination of all this suggests that also longer term river discharge signals are preserved in the marine sedimentary record offshore the great whale river in summary no major change in sediment discharge over the past 150 yr was observed however the offshore shift in the locus of sediment deposition suggests that a warming climate will lead to more energetic marine conditions less sea ice coverage and an increased offshore transport of terrestrial matter

terrigenous organic matter in holocene sediments from the central baltic sea nw europe abstract the baltic sea is an epicontinental sea surrounded by a catchment in boreal and sub boreal vegetation zones the isotopic composition 13c of organic carbon was in the range of 30 to 20 but contrary to our expectations had no statistically significant relation to lignin oxidation product yields 0 4 to 10 mg g 1 toc in a large set of baltic sea surface sediments the isotopic ratio thus may be inappropriate as an indicator for marine versus terrestrial organic carbon input into the baltic sea as in surface sediments we find no correspondence between lignin biomarker abundance 0 3 to 6 mg g 1 toc and 13c 30 to 24 5 of organic carbon in sediments from a core which brackets the late glacial and the holocene the relative contribution of terrestrial carbon as estimated from lignin oxidation product analyses increased steadily as soils and forests developed transgressive events of lake and marine stages are marked by enhanced input of terrestrial organic carbon there was no evidence that the terrestrial organic matter was altered significantly after sedimentation because although ad al v and ad al s varied between 0 3 and 0 7 there was no trend of increasing values downcore the amount and the composition of the sedimentary lignin as indicated by s v 0 3 to 0 9 and c v 0 2 to 5 6 changed according to the development of the vegetation after deglaciation and the effects of human activity in the late holocene signals in lignin input and composition thus correlate with the development of the vegetation with hydrographic changes and with human activities particularly with deforestation events

relationship between earthquake induced excess pore water pressure and strong ground motion observed in a monitored fill slope abstract the generation of excess pore water pressures during ground shaking can be an important earthquake induced landslide trigger we measured pore water pressures and seismic ground motion in filled slopes and examined their relationships obtained from 29 observed earthquakes we characterized pore water pressure and seismic waveforms by calculating several parameters that described their magnitudes and durations we demonstrate that whilst the instantaneous magnitude of strong ground motion is responsible for the generation of excess pore water pressure the magnitude of excess pore water pressure generated is related to the peak ground acceleration pga and arias intensity ai in the observed pga range of 0 12 1 9 m s2 the magnitude of peak ground velocity pgv also produced a strong correlation although a few exceptional events where long period component 1 s of seismic waves is dominant were observed lastly the time span over which excess pore water pressure continues to rise is affected by the duration of seismic ground motion our study shows how excess pore water pressures can be generated in fill slopes during seismic events this new knowledge could be used to improve future earthquake induced landslide hazard assessment

widespread landslides induced by the mw 5 1 earthquake of 11 may 2011 in lorca se spain abstract on 11 may 2011 a moderate magnitude mw 5 1 earthquake struck the city of lorca se spain and nearby areas causing notable damage injuries and fatalities field inspection of the area affected allowed the location and characterization of more than 250 induced landslides mainly of disrupted type rock soil falls disrupted soil slides and rock avalanches this number was very high when compared with the inventories of previous events of similar magnitude mw 4 7 to 5 0 in the zone and with the results of previous models for predicting slope behavior during earthquakes several factors are proposed here to explain the observed differences i the comparatively high magnitude mw 4 5 of a foreshock of the seismic series that may have weakened the slopes ii the high peak ground motion values recorded for these events and iii the occurrence of topographic site effects the results of this study point out the importance of including such effects as improvements in the models for studying the regional behavior of slopes

towards a sediment and organic carbon budget for hudson bay abstract a preliminary sediment and organic carbon budget is constructed for the hudson bay marine system based on published literature and new data collected from nine rivers and 13 sediment boxcores the budget considers the main inputs of terrestrial and marine components of sediment and organic carbon and the main sinks sediment burial and losses oxidation export to hudson strait sedimentation rates 0 032 0 23 g cm 2 yr 1 were estimated from 210 pb profiles and a sediment advection diffusion model in our cores and in two cores collected previously by lockhart et al lockhart w l et al 1998 fluxes of mercury to lake sediments in central and northern canada inferred from dated sediment cores biogeochemistry 40 163 173 sedimentation rates implied by the 210 pb profiles were verified against profiles of 137 cs and for some of the cores contaminant pb the sediment sink in hudson bay was estimated at 138 64 10 6 t a 1 by applying the average sedimentation rate to the area of active sedimentation in the bay 15 of the seafloor calculated according to a regional sedimentation map developed from seismic data josenhans h w et al 1988 preliminary seismostratigraphic and geomorphic interpretations of the quaternary sediments of hudson bay natural resources canada the known sediment sources to hudson bay include river input 11 6 6 10 6 t a 1 subaerial coastal erosion 8 4 10 6 t a 1 marine primary production 24 2 17 10 6 t a 1 and atmospheric deposition 0 5 10 6 t a 1 based on the available data the modern sediment input 44 3 18 10 6 t a 1 represents only about one third of the apparent sediment sink in hudson bay resuspension and lateral transport of shallow water deposits primarily glacigenic and winnowing from topographic highs likely consequences of the exceptional continuous relative sea level rsl fall in hudson bay provides a plausible source for the 116 10 6 t a 1 imbalance using organic carbon and 13 c values in the cores we estimate the burial of particulate organic carbon poc in sediments at 1 3 0 6 10 6 t c a 1 of which 80 is marine the importance of reworked glaciomarine carbon to the burial flux is difficult to estimate because modern autochthonous primary production provides a large source of poc to the system 16 1 7 10 6 t c a 1 and its degradation is not well constrained the 0 58 10 6 t c a 1 terrestrial carbon estimated to be transported as part of the redistributed sediment load accounts for almost one half the total terrigenous poc inputs to the bay if sediment and oc supply and burial in the hudson bay system are presently responding to the history of isostatic rebound as proposed here the task of predicting and measuring the additional consequences of river diversions and climate change e g sea ice permafrost runoff is rendered considerably more difficult

impact of tensile strength and incident angles on a soil slope under earthquake sv waves abstract the tensile strength and incident angles play important roles in seismically induced slope failures in this paper a new criterion for tension shear coupling is proposed based on several sets of relevant lab data and is verified using the experimental data provided by previous researchers this criterion can perfectly depict the tension region as well as the compression region in the entire stress space moreover the tension shear criterion was converted into an expression that could be directly used in a numerical method and it was verified by a numerical example in addition the sv waves were input using the equivalent nodal force method based on a viscous spring artificial boundary this process was implemented by the abaqus software and two numerical examples were used to verify this method subsequently based on the proposed new criterion and input method the impacts of the strength criterion and incident angles on an analysis of seismically induced slope failures were studied the results indicated that the evaluation of the tension shear region is extremely important in the analysis of the seismically induced slope failures the tensile strength of the seismically induced landslides was overestimated by the calculation of mohr coulomb criterion owing to the ambiguous description of the tensile failure or the tension shear failure the assessment of the slope stability was thus not conservative the incident angles of seismic waves affected the travel path and the directivity of slope seismic responses the sliding displacement of the slope side near the epicenter rose with increasing angles of wave incidence the critical slip surface deepened and the hazard aggravated therefore it is important to introduce both the tensile strength and incident angles when evaluating the stability of slopes subjected to seismic loads

on the applicability of available regression models for estimating newmark displacements for low to moderate magnitude earthquakes the case of the betic cordillera s spain abstract newmark displacement estimation is generally computed using empirical models these models are estimated from large datasets that mainly comprise moderate to high magnitude events mw 6 0 in this work we study the performance of several of these models to study moderate to low magnitude scenarios for this purpose data from the betic cordillera s spain with magnitudes ranging from mw 3 5 to 6 3 were used to compare with model predictions the results show that errors in the estimates depend on the magnitude of events or on the yielding acceleration considered to estimate the displacement the availability of an appropriate range of data magnitude and yielding acceleration when defining the regression model may overcome the differences due to specific characteristics of the seismotectonic context of the area where data derives from the results also show that performance of models including several ground motion predictors is better than those based on a single parameter regardless of the combination these predictors furthermore regression models with polynomial forms present a better performance than other functions based on the logarithm of these predictors finally new specific models for the betic cordillera are proposed especially suitable for low magnitude events

on far field occurrence of seismically induced landslides abstract earthquakes may induce landslides at large distances from the epicentral area in the last two decades there have been many studies of this phenomenon to determine the causes that contribute to the occurrence of landslides at very long distances from earthquake epicenter in this study which is based on previously published works a worldwide database comprising 270 earthquakes including 150 during the instrumental period was compiled to analyse the features of those landslides that occur at much further distances than maximum expected distances from the analysis of the compiled data it was observed that susceptible slopes can be grouped into five broad geological categories jointed rock marly clayey cohesive soils granular alluvial and or colluvial sediments volcanic soils and residual soil slopes these categories were equally likely to be associated with far field disrupted landslides whereas far field coherent landslides were more frequent on cohesive soil slopes other factors along with slope susceptibility may also contribute to far field landslides and increase the size of the area affected among these factors site effects antecedent rain and occurrence of seismic series have been cited the analysis of available data also showed that for events of the same magnitude far field disrupted landslides may occur at greater distances than coherent ones the same database has also been employed to determine for the first time the upper bound curves for the maximum observed epicentral distances of several types of landslides and the maximum area observed to be affected by landslides both based on the epicentral intensity of the events

coastal erosion vs riverine sediment discharge in the arctic shelf seas this article presents a comparison of sediment input by rivers and by coastal erosion into both the laptev sea and the canadian beaufort sea cbs new data on coastal erosion in the laptev sea which are based on field measurements and remote sensing information and existing data on coastal erosion in the cbs as well as riverine sediment discharge into both the laptev sea and the cbs are included strong regional differences in the percentages of coastal erosion and riverine sediment supply are observed the cbs is dominated by the riverine sediment discharge 64 45 106 t a 1 mainly of the mackenzie river which is the largest single source of sediments in the arctic riverine sediment discharge into the laptev sea amounts to 24 10 106 t a 1 more than 70 of which are related to the lena river in comparison with the cbs the laptev sea coast on average delivers approximately twice as much sediment mass per kilometer a result of higher erosion rates due to higher cliffs and seasonal ice melting in the laptev sea sediment input by coastal erosion 58 4 106 t a 1 is therefore more important than in the cbs and the ratio between riverine and coastal sediment input amounts to 0 4 coastal erosion supplying 5 6 106 t a 1 is less significant for the sediment budget of the cbs where riverine sediment discharge exceeds coastal sediment input by a factor of ca 10

isotopic constraints of sedimentary inputs and organic carbon burial rates in the saguenay fjord quebec abstract the saguenay fjord quebec has exceptionally high sedimentation rates resulting in up to 100 m thick holocene sequences filling some of its basins partly due the frequent occurrence of rapidly deposited layers landslides seismic events floods in the present study special attention is paid on the incidence of such events on organic carbon oc fluxes sources and burial rates using physical sedimentological geochemical and isotopic measurements on 4 sediment cores raised from the inner basin of the fjord and the adjacent baie des ha ha in these cores rapidly deposited layers rdl include notably a turbidite linked to a major earthquake in 1663 a landslide layer dating from 1971 saint jean vianney landslide and a flood layer from 1996 compared with background sediments rdl are characterized by low oc contents 3 contents 2 and low 13 c values in oc 13 c oc values 26 8 0 2 and c n ratios 17 7 1 7 in the pre industrial pre 1663 fjord sediments indicate that most sedimentary organic matter om was then of terrigenous origin paper mill activity during the 20th century has resulted in om fluxes growing almost exponentially until the mid 1960s when major changes in industrial practices and the implementation of environmental regulations during the 1970s and later on reduced the amount of industrial om discharged into the fjord this industrial om shows an isotopic signature of 26 34 0 02 and c n ratios 20 not unlike those of the regional terrestrial om oc burial rates since the 1663 earthquake varied between 20 and 290 gc m 2 yr 1 rdl seem to favour oc preservation in the fjord by reducing bioturbation and both oxic and anoxic oc degradation and by contributing themselves to higher carbon burial rates therefore transitional environments such as the saguenay fjord could represent significant long term carbon sinks

earthquake induced landslides in central america central america is a region of high seismic activity and the impact of destructive earthquakes is often aggravated by the triggering of landslides data are presented for earthquake triggered landslides in the region and their characteristics are compared with global relationships between the area of landsliding and earthquake magnitude we find that the areas affected by landslides are similar to other parts of the world but in certain parts of central america the numbers of slides are disproportionate for the size of the earthquakes we also find that there are important differences between the characteristics of landslides in different parts of the central american isthmus soil falls and slides in steep slopes in volcanic soils predominate in guatemala and el salvador whereas extensive translational slides in lateritic soils on large slopes are the principal hazard in costa rica and panama methods for assessing landslide hazards considering both rainfall and earthquakes as triggering mechanisms developed in costa rica appear not to be suitable for direct application in the northern countries of the isthmus for which modified approaches are required