mud volcano growth by radial expansion examples from onshore azerbaijan abstract we investigated the mode of growth of flat topped mud volcanoes through the study of three active edifices onshore azerbaijan they are the bozdag guzdek the ayazakhtarma and the akhtarma pashaly mud volcanoes the three edifices are up to 80 m high and 3 km wide and have eruptions with recurrent times from a few months to a few years surface changes during and between eruptions were documented by a combination of mapping from satellite pictures repeated direct observation over five years and structural analysis in addition resistivity profiles and microgravity measurements were used to decipher their subsurface geometries we interpret the flat topped character of the mud volcanoes as the result of rapid isostatic readjustment of a brittle surface crust

controls on the geomorphic expression and evolution of gryphons pools and caldera features at hydrothermal seeps in the salton sea geothermal field southern california abstract in the salton sea geothermal field in southern california expulsion of gas sediment and water creates unique geomorphic features similar to those seen on the surface of dormant mud volcanoes these include pools of water or highly fluid mud named mud pots and 0 5 to 2 5 m tall gryphons the features vary in size shape and type of eruptive activity and change form over time to evaluate controls on the surface morphology and evolution of these features we used repeated differential gps surveys observations of eruptive activity and measurements of erupted mud properties to document the physical characteristics and changes in the system over a 28 month period we find that the morphology of the gryphons is primarily a function of the mud expulsion style taller 1 5 m to 2 4 m gryphons form where narrower vents 5 cm to 15 cm diameter expel mud to the surface in discrete strombolian type eruptions caused by individual gas bubbles pushing mud up through the gryphon conduit and exploding at the surface smaller 0 6 m to 1 5 m gryphons form where wider vents allow a greater amount of gas to pass through which creates 0 25 to 1 m diameter mud craters that bubble continuously often from multiple points within the crater although viscous mud is required to create these positive topographic features variations in erupted mud temperature 30 c to 68 5 c density 1 44 g cm 3 to 1 59 g cm 3 and water content 36 to 44 between different gryphons did not correlate with gryphon size all the active gryphons experienced periods of growth and erosion over the study period due to changes in the degree of activity or small variations in the vent locations within the gryphons but the net change in height distributions over time was negligible pools directly adjacent to gryphon clusters are surficial features whose water level depends on seasonal rainfall and temperature isolated pools are also present and do not show similar response to seasonal changes suggesting that these pools are connected to the local groundwater system although changes in vent morphology and activity do occur the new data demonstrate that the system is steady state in terms of the height distribution of the gryphons and the location of the main seeps most of the gryphons occur in clusters that are surrounded by caldera like depressions that range from 10 to 25 m in diameter mud expelled from the gryphons is largely contained within the caldera depressions and we infer that subsidence of the calderas accounts for the lack of large scale build up of material in the surrounding area this study provides the first examination of the processes controlling the morphology of these features and the results may help to understand the dynamics and temporal evolution of gryphons which are found in both hydrothermal systems and on dormant mud volcanoes

global methane emission through mud volcanoes and its past and present impact on the earth s climate mud volcanism is an abundant global phenomenon whereby fluid rich low density sediments extrude both on land and offshore methane which generally exceeds 90 vol of the gas phase is emitted at high rates during and after emplacement of the mud domes and is known for its high global warming potential gwp this comprehensive estimate of the annual contribution of mud volcano degassing assesses the significance of mud volcanism for the accumulation of greenhouse gases in the atmosphere a first order estimate for the earlier pre anthropogenic volume of methane released through mud volcanoes further supports their profound effect on the earth s climate since at least the paleozoic 570 ma

the structure and geomorphology of the dashgil mud volcano azerbaijan the large scale and small scale 10 m structure and geomorphology of the active dashgil mud volcano in central azerbaijan have been studied through historical records it is known that this mud volcano has major eruptions every 6 32 years the activity observed during two field trips in 1995 consisted of low energy venting and debouching of mud water oil and gas from three mud pools salses and about 20 individual cones gryphons located on the summit plateau of the mud volcano besides the bubbling mud pools ranging from 30 to 75 m across and the cones ranging from 0 8 to 3 m height a 200 m long string of about 10 sinter mounds was found on the summit plateau the internal structure of the mud volcano and the processes responsible for the observed dashgil geomorphology are discussed assuming the dashgil mud volcano to be continuously active with an average methane production similar to that observed in 1995 between the rare major eruptions we have conservatively estimated the dashgil mud volcano to produce an annual amount of at least 800 sm3 standard cubic metres of gas mainly methane which is emitted directly into the atmosphere this estimate indicates that the natural contribution of atmospheric greenhouse radiatively active gases from the world s terrestrial and submarine mud volcanoes is highly significant

the nature and hydrogeologic significance of mud diapirs and diatremes for accretionary systems in accretionary wedges often morphologically similar sedimentary intrusions when observed by remote geophysical means may have one of two quite different driving mechanisms and a highly variable significance for the regional hydrogeologic picture for example mud diapirs are driven by buoyancy forces that arise from bulk density contrasts in them mud and pore fluid upwell en masse and fluid migration is a related sometimes important but generally subsidiary process in contrast diatremes contain sediments fluidized during rapid fluid advection and are forcibly and directly driven by the hydrogeologic system the nature of fluid input from local and exotic source regions can therefore strongly affect sedimentary intrusive processes and vice versa this complicates the process of defining the main features of the hydrogeological systems operating in accretionary wedges focused vertical advection through steep sided piercement mud diapirs requires conduit systems otherwise flow will be diffuse and directed more horizontally out of the low permeability mud mass however where the permeability of the overburden is less than that of the diapir the whole diapir may act as a conduit apart from this special case conduits will be associated with highly anisotropic scaly fabrics that can sometimes develop in the marginal shear zone of diapirs scaly fabrics form during deformation and compaction of a mud matrix under conditions of constant or increasing effective stress however the effective stress path can be complex as it is both controlled by the relative rates of upward intrusion and burial by sedimentation and or structural thickening and the hydrogeologic system due to this it appears likely that even in a geographically related group of diapirs effective stress histories will vary widely between intrusions so that some can form advective pathways for fluids and some cannot mixed systems of behavior may also be present with local diatremes developing within diapirs above the terminations of conduit systems and rapidly expanding methane gas pockets the potentially heterogeneous near surface behavior may be why the surface manifestations of sedimentary intrusions are so variable when observed in the field diatremes can also form separately as large primary features above any structural or stratigraphic conduit that rapidly expels water or gas into the base of an unlithified sediment column when active large diatremes require enormous quantities of fluid water or gas to drive them particularly if they are long lived features and hence are a direct indication of at least an episodically vigorous hydrogeologic system

on the response of the fjord gullmaren under ice cover an analysis is presented of current salinity and temperature records obtained under ice cover near the mouth of the fjord gullmaren on the sweden skagerrak coast results are compared with an earlier analysis from spring and summer conditions shaffer and djurfeldt 1983 large amplitude vertical fluctuations of the density field of several week periods regularly occurring in the winter season appear to be associated with variations in the baltic sea outflow the local alongshore wind seems to force motions of several day periods in the fjord even under ice cover through interaction with the coastal zone internal seiches prominent features during spring and summer are essentially absent under ice cover which implies that these motions are forced most effectively by the direct action of the local wind on the fjord a method is presented for the determination of significance levels in empirical orthogonal function analysis in the frequency domain

reply to comment by a kopf on methane emission from the mud volcanoes of sicily italy and notice on ch4 flux data from european mud volcanoes

shallow gas transport and reservoirs in the vicinity of deeply rooted mud volcanoes in the central black sea abstract the principal objective of this paper is to understand the gas migration process and the structures of mud volcanoes in the central black sea multichannel seismic lines were acquired across 6 mud volcanoes in the central black sea msu yuzhmorgeologiya malyshev kornev goncharov and vassoevitch based on a high resolution seismic processing we analyzed acoustic anomalies and studied near surface sediment structures of these mud volcanoes four types of pathways for gas and fluid migration and three types of gas reservoirs were recognized a regional bottom simulating reflection bsr seems to be absent in most parts of the study area however a clear bsr was observed in one of the seismic profiles the free gas migrating upwards along these pathways were sealed by gas hydrates or fine grained sediments in the gas hydrate stability zone four seismic units were separated according to a suggested age model and identified seismic facies combining with the possible sedimentary processes of the central black sea we try to reveal the active mechanism of these mud volcanoes these mud volcanoes reveal two to three major active stages these active stages might be related to distinct sea level falls which seem to be one of the main trigger factors of the mud volcano eruptions in the central black sea a structural model for the msu mud volcano was presented with respect to mechanisms of gas migration and the origin of the gas

martian mud volcanism terrestrial analogs and implications for formational scenarios the geology of mars and the stratigraphic characteristics of its uppermost crust mega regolith suggest that some of the pervasively occurring pitted cones mounds and flows may have formed through processes akin to terrestrial mud volcanism a comparison of terrestrial mud volcanism suggests that equivalent martian processes likely required discrete sedimentary depocenters volatile enriched strata buried rheological instabilities and a mechanism of destabilization to initiate subsurface flow we outline five formational scenarios whereby martian mud volcanism might have occurred a rapid deposition of sediments b volcano induced destabilization c tectonic shortening d long term load induced subsidence and e seismic shaking we describe locations within and around the martian northern plains that broadly fit the geological context of these scenarios and which contain mud volcano like landforms we compare terrestrial and martian satellite images and examine the geological settings of mud volcano provinces on earth in order to describe potential target areas for piercement structures on mars our comparisons help to evaluate not only the role of water as a functional component of geological processes on mars but also how martian mud volcanoes could provide samples of otherwise inaccessible strata some of which could contain astrobiological evidence

the circular uneged uul structure east gobi basin mongolia geomorphic and structural evidence for meteorite impact into an unconsolidated coarse clastic target abstract the uneged uul structure is a 10 km circular complex multi ridged domal feature in the unegt subbasin of the east gobi basin southeastern mongolia as revealed by remote sensing and recent field reconnaissance the central part of the uneged uul structure comprises a complex central peak of outward radiating curved ridges composed of stratigraphically uplifted greenschist facies basement schists surrounded by an annular moat the most prominent feature of the structure is a central annular ridge 3 km in diameter composed of pebble boulder conglomerates and gravels of the upper jurassic sharilyn formation surrounded by three outer domal ridges composed of lower cretaceous conglomeratic sandstones and gypsum clays jurassic conglomerates forming the main part of the central annular ridge show effects of severe internal deformation the original population of pebbles cobbles and boulders appears moderately displaced and mostly broken but nowhere aligned along shear planes or foliated primary sedimentary features such as cross lamination or imbrication have been obliterated we explain this penetrative brecciation as a result of dissipative shearing caused by a strong and rapid singular event that in magnitude was beyond the range of the common crustal tectonics recorded elsewhere in this region disrupted and chaotically distributed conglomeratic sandstone beds in the central annular ridge dip in highly variable directions on a local scale but show an apparent se nw trend of bedding plane alignment further outside the tilted and uplifted upper jurassic to lower cretaceous strata of the domal area are overlain by the flat lying upper cretaceous which stratigraphically constrains the timing of deformation at the uneged uul structure to most likely the early cretaceous endogenic formation models such as magmatism and salt gypsum or mud diapirism fail to explain the nature of the uneged uul structure the uneged uul structure bears a set of geomorphic and structural features resembling those at some eroded complex impact structures on earth morphologically similar central peaks are observed at the spider and matt wilson impact structures in australia the central annular ridge reminds of that at gosses bluff in australia the outer domal ridges might correspond to ring like features as known from tin bider in algeria we therefore cautiously propose that an impact may have produced the uneged uul feature causing structural uplift 1000 m of basement rocks at its center so far no convincing evidence for shock metamorphism could be proven by field work and petrographic analyses however it is likely that at the time of the deformation event the unconsolidated conglomerates were highly porous and possibly immersed in groundwater buffering the propagation of sudden stress reducing deformation further studies will be in order to unravel the nature of the uneged uul structure which should be considered a promising possible impact structure

mud volcanoes the most important pathway for degassing deeply buried sediments abstract this paper discusses the nature of the phenomenon of mud volcanism with respect to degassing of deeply buried sediments mud volcanoes are defined as geological structures and their main elements are described based on the nature of activity mud volcanoes are grouped in to three main types and the relationship between each type and corresponding morphological expression is discussed the presented up to date data of the world geographical distribution of mud volcanoes show that they approximate to 1800 individuals a detail overview of geological environments in which they occur helps to deduce some necessary conditions for mud volcano formation the basic mechanisms of mud volcano formation are discussed specifically the fluid pressure hypothesis and some triggering events are identified the most common investigation approach and some criteria for recognizing of a submarine mud volcano on side scan sonar records and seismic sections are given mud volcanism in the mediterranean ridge an accretionary complex and black sea abyssal plane a back ark basin with tectonic regime of extension are described as case studies to show variety in morphology and common factors in development of mud volcanoes the manifestation of continuous gas migration through mud volcanoes is clarified and the attempt made to quantify the gas release shows that mud volcanoes are one of the significant natural sources of atmospheric methane emitting a total amount of about 10 3 to 12 6 tg annually

when mud volcanoes sleep insight from seep geochemistry at the dashgil mud volcano azerbaijan the worlds 1500 mud volcanoes are normally in a dormant stage due to the short duration of eruptions their dormant stage activity is often characterized by vigorous seepage of water gas and petroleum however the source of the fluids and the fluid rock interactions within the mud volcano conduit remain poorly understood in order to investigate this type of activity we have combined satellite images with fieldwork and extensive sampling of water and gas at seeping gryphons pools and salsa lakes at the dashgil mud volcano in azerbaijan we find that caldera collapse faults and e w oriented faults determine the location of the seeps the seeping gas is dominated by methane 94 9 99 6 with a 13c v pdb in the 43 9 to 40 4 range consistent throughout the 12 analysed seeps ethane and carbon dioxide occur in minor amounts seventeen samples of seeping water show a wide range in solute content and isotopic composition pools and salsa lakes have the highest salinities up to 101 043 ppm cl and the lowest 18o v smow values 1 4 the mud rich gryphons have low salinities 18 000 ppm cl and are enriched in 18o 18o 4 6 the gas geochemistry suggests that the gases migrate to the surface from continuously leaking deep seated reservoirs underneath the mud volcano with minimal oxidation during migration however variations in gas wetness can be ascribed to molecular fractionation during the gas rise in contrast the water shows seasonal variations in isotopic composition and surface evaporation is proposed as a mechanism to explain high water salinities in salsa lakes by contrast gryphons have geochemical signals suggesting a deep seated water source these results demonstrate that the plumbing system of dormant mud volcanoes is continuously recharged from deeper sedimentary reservoirs and that a branched system of conduits exists in the shallow subsurface while the gas composition is consistently similar throughout the crater the large assortment of water present reflects the type of seep i e gryphons versus pools and salsa lakes and their location within the volcano our data highlight the importance of a carefully planned sampling strategy when the target is water geochemistry whereas the methane content and isotopic composition is relatively independent of the particular seep morphology

relations between mud volcanoes thrust deformation slope sedimentation and gas hydrate offshore north panama abstract seamarc ii swath mapping and migrated seismic reflection data show a high concentration of mud volcanoes in the primary sediment depocentre along the lower slope of a thrust belt offshore north panama the mud volcanoes are 0 4 2 0 km wide sonar reflectivity backscattering sediment cores and seismic stratigraphic relations indicate that the depocentre contains thick sequences of basinal turbidites which are ponded between the anticlinal ridges the ridges are composed of the deformed turbidites of the colombian basin and exhibit a strong bottom simulating reflector bsr apparently associated with a gas hydrate layer based on the concentration of mud volcanoes along the crests of the anticlinal ridges in the depocentre and the structural position of the bsr we suggest that folding along the deformation front sediment ponding leading to differential loading methane migration and accumulation in the anticlines and gas hydrate formation are important factors in the development of mud volcanoes in this region

cyclic activity of mud volcanoes evidences from trinidad se caribbean fluid and solid transfer in mud volcanoes show different cyclic phases of activity including catastrophic events and periods of relative quiescence characterized by moderate activity this is notably well shown by the compilation of historical data onshore trinidad it appears that each eruptive mud volcano has its own period of catastrophic activity and this period is variable from one volcano to another the frequency of the eruptions seems essentially controlled by local pressure regime within the sedimentary pile the dynamics of expulsion of the mud volcanoes during the quiescent phases has been studied with the help of temperature measurements within the mud conduits the mud temperature in these conduits is notably concurrently controlled by the gas flux endothermic gas depressurizing induces a cooling effect and by the mud flux mud is a vector for convective heat transfer complex temperature distribution was observed in large conduits and pools especially in the bigger pools the temperature distribution characterizes convective cells with an upward displacement of mud above the deep outlet and ring shaped rolls associated with the burial of the mud on the flanks of the pools in tube like shaped narrow conduits the temperature is more regular but we observed different types of profiles with either downward increasing or decreasing temperatures near constant to even negative gradients compared to the general temperature gradient are typical for very dynamic fluid systems the temperature profiles varied from one place to another as well as over time the temperatures measured within the conduits and their base show that the fluid flow is not constant but highly variable through short time periods we observed locally a significant daily change of the temperature of the expelled mud which shows also that the mud flux is changing very rapidly due to the migration dynamics of the mud in fracture systems we also observed very short time period cyclic variations with a frequency of several minutes these high frequencies temperature changes could be related to the dynamics of two phase flows gas and mud through the mud volcano conduits

development and growth of recently exposed fumarole fields near mullet island imperial county california abstract new field observations aerial surveys lidar measurements and laboratory studies of mud samples 2006 to 2012 are reported of several formerly submerged fumarole complexes that are presently undergoing surface exposure as the salton sea level drops some remain submerged as of this writing 2012 the fumarole fields range in area from 1000 to 50 000 m2 they consist of hundreds of warm to boiling hot gryphons mud volcanoes salses mud pots and countless active gas vents unusually shaped mud volcanoes in the form of vertical tubes with central vents were observed in many places since exposure began in 2007 the surface morphology has changed dramatically with a trend toward more and growing gryphons larger mud pots and the development of sulfur vents chemical analysis of mud from several gryphons revealed the presence of the ammoniated sulfate minerals boussingaultite and lecontite among other more common sulfates with other geothermal features the fumaroles define a well defined lineament marking the trace of a probable fault a model for the development of gryphon morphology is presented

significance of mud volcanism 1 mud volcanism and diapirism have puzzled geoscientists for 2 centuries they have been described onshore and offshore in many places on earth and although they occur in various tectonic settings the majority of the features known to date are located in compressional tectonic scenarios this paper summarizes the main thrusts in mud volcano research as well as the various regions in which mud volcanism has been described mud volcanoes show variable geometry up to tens of kilometers in diameter and several hundred meters in height and a great diversity regarding the origin of the fluid and solid phases gas predominantly methane water and mud may be mobilized at subbottom depth of only a few meters but in places can originate from several kilometers depth with minor crustal or mantle input the possible contribution of mud extrusion to global budgets both from quiescent fluid emission and from the extrusive processes themselves is important in regions where mud volcanoes are abundant such as the collision zones between africa and eurasia fluid flux through mud extrusion exceeds the compaction driven pore fluid expulsion of the accretionary wedge also quiescent degassing of mud volcanoes may contribute significantly to volatile budgets and hence to greenhouse climate

methane emission from the mud volcanoes of sicily italy 1 mud volcanoes represent the largest expression of natural methane release into the atmosphere however the gas flux has never been investigated in detail methane output from vents and diffuse soil degassing is herewith reported for the first time measurements were carried out at 5 mud volcano fields around sicily italy each mud volcano is characterized by tens of vents and bubbling pools in the quiescent phase methane emission from single vents ranges between 0 01 and 6 8 kg day diffuse soil leakage around the vents is in the order of 102 104 mg m 2 d 1 an exceptional flux of 106 mg m 2 d 1 was recorded close to an everlasting fire soil ch4 flux is positive even at large distances from the mud volcano fields suggesting a diffuse microseepage over wider areas a total of at least 400 tons ch4 per year can be estimated over the area investigated alone 1 5 km2

modelling fluid flow in clastic eruptions application to the lusi mud eruption abstract clastic eruptions involve the rapid ascension of sedimentary clasts together with fluids gas and or liquid phases that may further deform and brecciate the host rocks these fluids transport the resulting mixture called mud breccia to the surface such eruptions are often associated with geological structures such as mud volcanoes hydrothermal vent complexes and more generally piercement structures they involve various processes acting over a wide range of scales which makes them a complex and challenging multi phase system to model although piercement structures have been widely studied and discussed only a few attempts have been made to model the dynamics of such clastic eruptions the ongoing lusi mud eruption in the east java back arc basin which began in may 2006 is a spectacular large scale clastic eruption the lusi eruptive behaviour has been extensively studied over the past decade and thus represents a unique opportunity to better understand ongoing clastic eruptions and thus fossil clastic systems we use both analytical formulations and numerical models to investigate simple relationships between the mud breccia properties density viscosity gas and clast content and the volumetric flow rate our results show that the conduit radius of such piercement systems cannot exceed a few metres at depth and that clasts if not densely packed will not affect the flow rate when they are smaller than a fifth of the conduit size using published data for the annual gas fluxes at lusi we infer a maximal depth at which exsolution starts this occurs between 1800 m and 3200 m depth for methane and between 750 m and 1000 m for carbon dioxide based on annual gas fluxes we estimate that the conduit radius should be no larger than 1 5 m to match the maximal mud discharge recorded at lusi

rankine models for time dependent gravity spreading of terrestrial source flows over subplanar slopes geological mass flows extruding from a point source include mud lava and salt issued from subsurface reservoirs and ice from surface feeders the delivery of the material may occur via a salt stock a volcanic pipe for magma and mud flows or a valley glacier for ice all these source flows are commonly skewed by a superposed far field velocity vector imposed by the topographic slope and thus develop plumes having a wide range of shapes the morphological evolution of the perimeter of the plumes in plan view can be simulated by varying the key parameters in a simple analytical flow description on the basis of rankine equations our model systematically varies the strength of the point source relative to the downslope far field velocity of its expelled mass the flow lines are critically controlled by the relative speed of the two rates which can be concisely expressed by the dimensionless rankine number rk introduced in this study for steady flows plume widths can be expressed as a function of rk the viscosity of the rock mud or lava mass involved in the gravity flow affects rk and thus the appearance of the plumes for unsteady source strength rk becomes time dependent and the plume width varies over time the model flow shapes suggest that the plume shapes of natural gravity flows of terrestrial surface materials mud lava salt and ice commonly express fast initial flux of the source followed by an exponential decline of the source strength flows having initially higher rk but otherwise equal life cycles create broader plumes peaks in the source flux due to magmatic pulsing during the eruption cycle can explain the formation of pillow lavas rather than instantaneously reaching full strength before declining some natural source flows start by swelling slowly leading to the creation of unique plume shapes like a flying saucer

geochemistry of gases and waters discharged by the mud volcanoes at paterno mt etna italy approximately 20 km south of mt etna craters at the contact between volcanic and sedimentary formations three mud volcanoes discharge co2 rich gases and na cl brines the compositions of gas and liquid phases indicate that they are fed by a hydrothermal system for which temperatures of 100 150 c were estimated by means of both gas and solute geothermometry the hydrothermal system may be associated with co2 rich groundwaters over a large area extending from the central part of etna to the mud volcanoes numerous data on the he ch4 co2 composition of the gases of the three manifestations sampled over the past 5 years indicate clearly that variations are due to separation processes of a co2 rich gas phase from the liquid the effects of these processes have to be taken into account in the interpretation of the monitoring data collected for the geochemical surveillance of etna volcano

the mud volcanoes of pakistan marine geologic investigations on the arabian sea by bundesanstalt fur geowissenschaften und rohstoffe bgr in 1995 and 1998 and land expeditions in 1998 and 1999 to the coastal regions of the makran desert pakistan have extended the knowledge of the aerial distribution of mud volcanoes these structures rise from under compacted formations within the regional accretionary prism which is built by the subduction of the oceanic crust of the arabian sea and its km thick sedimentary load the occurrence of mud volcanoes is limited to the abyssal plain near the accretionary front to the coastal region of the makran desert and to a region in the interior of the desert to the south to southeast of the so called hinglay synform the location of mud volcanoes in pakistan is clearly tied to fault systems mud volcanoes are conspicuously absent on the lower slope of the accretionary prism where thick gas hydrate layers have developed the presence of large gas plumes emerging from the seafloor landward of the gas hydrate stability zone at water depths of less than 800 m points to a redirection of fluids from depth which might explain the absence of mud volcanoes along the lower slope

structure and emplacement of mud volcano systems in the south caspian basin the term mud volcano system is coined to describe the set of structures associated with a constructional edifice mud volcano and feeder complex that connects the volcano to its source stratigraphic unit three dimensional 3 d seismic data from the south caspian basin are used to investigate the structural elements and evolution of these systems mud volcano systems initiate via early kilometer scale biconic edifices termed pioneer cones these are fed by fluidization pipes tens of meters in width subsequent kilometer scale mud volcanoes grew via persistent extrusion fed by numerous additional fluidization pipes injected in the country rock this subvolcanic intrusion complex creates a densely intruded cylindrical zone similar in cross section to gryphon swarms observed at an outcrop onshore wall rock erosion and compaction of the intruded zone leads to the collapse of a downward tapering cone enveloping the cylindrical zone capped by ring faults that define a kilometer scale caldera that downthrows the overlying mud volcano mud volcanoes get buried during basin subsidence and can look like intrusive laccoliths at first glance on seismic data reactivation of mud flow through a conduit system generates a stack of superimposed mud volcanoes through time large volcanoes continue to dewater during burial and may locally remobilize this model of mud volcano evolution has similarities with igneous and salt tectonic systems to reduce drilling and geologic uncertainty mud volcano system extent and impacts on a reservoir can be assessed on 3 d seismic data simon stewart received his ph d from the imperial college london in 1992 in 1992 2000 he was seismic interpreter at amerada hess in support of exploration and appraisal drilling in the north sea in 2000 he moved to bp and has since worked on structural geology and well planning in the americas middle east and the former soviet union his special interest is in the integration of structural geology and seismic interpretation richard davies received his ph d from the university of edinburgh in 1995 in 1995 2003 he was with mobil and exxonmobil working on field development and exploration the north sea the west of shetlands and the west niger delta deep water slope in 2003 2005 he was a senior lecturer in earth sciences at cardiff university united kingdom currently he is professor and director of cerees center for research into earth energy systems durham university united kingdom his special interest is in seismic scale expression of fluid migration and diagenesis

three dimensional seismic investigations of the sevastopol mud volcano in correlation to gas fluid migration pathways and indications for gas hydrate occurrences in the sorokin trough black sea new 3 d seismic investigations carried out across the sevastopol mud volcano in the sorokin trough present 3 d seismic data of a mud volcano in the black sea for the first time the studies allow us to image the complex three dimensional morphology of a collapse structured mud volcano and to propose an evolution model the sevastopol mud volcano is located above a buried diapiric structure with two ridges and controlled by fluid migration along a deep fault system which developed during the growth of the diapirs in a compressional tectonic system overpressured fluids initiated an explosive eruption generating the collapse depression of the sevastopol mud volcano several cones were formed within the depression by subsequent quiet mud extrusions although gas hydrates have been recovered at various mud volcanoes in the sorokin trough no gas hydrates were sampled at the sevastopol mud volcano a bsr bottom simulating reflector is missing in the seismic data however high amplitude reflections bright spots observed above the diapiric ridge near the mud volcano at a relatively constant depth correspond to the approximate depth of the base of the gas hydrate stability zone bghsz thus we suggest that gas hydrates are present locally where gas fluid flow occurs related to mud volcanism i e above the diapir and close to the feeder channel of the mud volcano depth variations of the bright spots of up to 200 ms twt might be caused by temperature variations produced by variable fluid flow

effects of bedrock lithology and subglacial till on the motion of ruth glacier alaska deduced from five pulses from 1973 2012 a pulse is a type of unstable glacier flow intermediate between normal flow and surging using landsat mss tm and etm imagery and feature tracking software a time series of mostly annual velocity maps from 1973 to 2012 was produced that reveals five pulses of ruth glacier alaska peaks in ice velocity were found in the 1981 1989 1997 2003 and 2010 approximately every 7 years during these peak years the ice velocity increased 300 from approximately 40 m yr to 160 m yr and occurred in an area of the glacier underlain by sedimentary bedrock based on the spatio temporal behavior of ruth glacier during the pulse cycles we suggest the pulses are due to enhanced basal motion via deformation of a subglacial till the cyclical nature of the pulses is theorized to be due to a thin till with low permeability that causes incomplete drainage of the till between the pulses followed by eventual recharge and dilation of the till these findings suggest care is needed when attempting to correlate changes in regional climate with decadal scale changes in velocity because in some instances basal conditions may have a greater influence on ice dynamics than climate

mud volcanoes in deepwater nigeria abstract detailed study of 3d seismic data from deepwater nigeria has revealed the presence of features interpreted to be mud volcanoes they occur in an upper slope environment seen as 1 2 km circular features at the seabed seabed cores from the mud volcanoes contain oil gas and sand shale clast content richer than the seabed background pliocene fossils have been identified in the cores demonstrating transport of material from depth the features show a high seabed seismic amplitude above a chimney of chaotic seismic reflections and data wipe out the mud volcanoes in the study area shows two distinct clusters located over deeper structural culminations four active mud volcanoes area 1 are located above a rollover anticline in the central part of the area cuspate listric faults reach the seabed on the up slope side of these mud volcanoes four abandoned mud volcanoes have also been identified with progressively older ages towards the crest of the underlying structure these abandoned features are associated with an extremely chaotic seismic signature a combination of over pressured carrier beds and low integrity top seals are believed to be responsible for the formation of these mud volcanoes it is further believed that gas expansion subsequent to seal failure was the main driving force for what must have been violent eruptions the long lived mud volcano activity over the deep structural closure suggests a plumbing system that focuses on escaping compaction water and hydrocarbons through time in the south west of the study area another cluster of five mud volcanoes is located above a shale diapir the seabed expression of the members of this cluster is more varied some show a positive relief at the seabed while others show circular depressions the largest feature represents an assemblage of many smaller mud volcanoes with a common root system their seismic expression is also different from that of area 1 with a well defined sediment wedge at surface and a shallower root system these features are believed to represent a less violent type of mud volcano characterised by ductile flow tectonic stress due to growth of the underlying diapir is thought to have played an important role during eruption in addition to focused methane escape and the low mechanical strength of the overburden

an experimental setup for fluid venting in unconsolidated sediments new insights to fluid mechanics and structures abstract focused outflow of water at the seafloor termed seepage or fluid venting is a widely recognized global phenomenon in an effort to better understand the mechanisms by which fluid flow related structures form we performed laboratory seepage experiments using samples representing a broad range of grain sizes and hydraulic conductivities 10e 3 to 10e 7 m s detailed observations led to the recognition of a typical often repeated progression of fluid flow structures that form during processes of increasing and decreasing hydraulic gradients the development of fluid flow structures like macro pores conduits and pipes is strongly dependant upon cohesion but is unrelated to grain size variations from sample to sample partial liquefaction leads to permanent changes in the grain fabric and to an increase in hydraulic conductivity our observations explain the longevity of seep sites and systematic relationships between hydraulic gradients grain fabric appearance and hydraulic conductivity that could be used to estimate flow rates based on structural findings

evidence of late holocene mud volcanic eruptions in the modena foothills northern italy among natural hazards mud volcanoes can damage property and infrastructures and affect hillslope evolution at different spatial and temporal scales the results of 10 year long multidisciplinary i

chemistry of groundwater from mud volcanoes in parts of upper benue trough northeastern nigeria mud volcanoes grouped into 14 fields are found in southern gombe part of the cretaceous upper benue trough filled with early cretaceous continental deposits and late cretaceous marine deposits having a history of magmatism dating from albian to pleistocene they are mostly of small sizes having cones not exceeding one and half metres in height and diameters ranging from 0 5 to 8 m at base as well as pools with muddy water and mudflows were encountered results of the study show that the cationic and anionic concentration varies as follows ca2 8 26 46 4 mg l mg2 1 16 20 mg l na 18 6 4789 mg l k 9 4 134 mg l fe 0 02 5 74 mg l hc 3 126 3111 mg l cl 5 2625 mg l so 4 2 12 5 16 9 mg l co 3 2 3 2040 mg l and sio2 7 45 6 mg l the study also reveals that the water issuing from the mud volcanoes in most cases is highly alkaline ph ranges from 7 94 to 8 99 saline tds varies from 140 to 1620 mg l very hard th varies from 102 to 1180 mg l and belongs to five hydrochemical facies namely na hco3 na hco3 cl na ca hco3 na cl co3 hco3 and ca na hco3 the dominant hydrochemical facies is na hco3 while ca na hco3 is the minor water type statistical correlation reveals positive correlation between most of the parameters with the exception of ca2 mg2 and so 4 2 all other parameters are far above the world health organisation standards for drinking water these waters are mineralised and are not considered to be suitable for drinking and domestic purposes but may be considered for therapeutic purposes

sector collapse of mud volcanoes azerbaijan abstract field data collected from mud volcanoes in azerbaijan are used to describe a process in mud volcano development that involves portions of the constructional edifices collapsing outwards in thin skinned9 slides these events create kilometre scale scarps that are tens of metres in height arcuate in plan view elongate and facing downdip similar morphological features occur on igneous volcanoes and have been described as sector collapse9 structures the largest sector collapses in igneous volcanoes involve some 10 12 tons of mobilized material equivalent structures in mud volcanoes are several orders of magnitude smaller we employ a shape parameter that can be utilized in field and satellite based mapping to distinguish between slope failure and eruptive deposits three mud volcanoes with kilometre scale sector collapses are described and controlling mechanisms are reviewed the updip domains of these collapses are characterized by fluid escape showing that there is also linkage to deeper mud volcano structure the observations are reconciled in a model consisting of a deflating mud chamber that triggers thin skinned sector collapse the updip domain of the sector collapse is localized above a deep seated zone of volume loss and the downdip domain of the collapse runs down the edifice flank onto the surrounding plain

mud volcanoes in central italy subsoil characterization through a multidisciplinary approach abstract mud volcanoes are common geological phenomenons observed worldwide as in italy they are well described in the scientific literature for their morphological tectonic and hydrogeological features they represent not only a relevant geological and geomorphological interest but also not negligible elements of hazard and risk associated with the presence of soft and pliable sediments and with the possible unexpected emission of gas and mud therefore the understanding of their structure and hydrogeological circuits in the subsurface is an important key to define hazard and risk conditions in the adjacent areas this paper deals with a multidisciplinary study including geophysical and hydrochemical surveys undertaken at the pineto central italy mud volcano site to achieve an interpretative conceptual model explaining the shallow upward migration of deep mud fluids shallow electrical and seismic imaging of the mud volcano was obtained using two dimensional and three dimensional 2d 3d electrical resistivity tomography and 2d reflection seismic surveys the hydrochemical properties of the rising fluids were assessed by means of seasonal measurements of the chemical physical parameters the concentrations of major ions and some natural isotopes this mud volcano or mud lump appears as a dome of about 15 10 m in size the height of the crater is 2 m approximately while the diameter of the crater is 2 5 m emission of fluids and solids cold brine mud gas occurs from this crater upper pliocene lower pleistocene foredeep pelitic deposits over compacted clays with silty sandy levels overlain by clayey silty deposits crop out in the area the survey results seem to reveal that the uprising of deep fluids does not occur exactly below the mud volcano at present instead a high conductivity body is present within a fractured zone in the pelitic deposits at 60 m approximately to the ene the probable occurrence of a high permeability layer approximately between 20 and 30 m below ground level confined by clay deposits gives rise to an overpressured mud fluids reservoir mud fluids appear to be flowing toward the surface from the reservoir up to the mud volcano crater the interpretative conceptual model proposed by the authors is a first attempt to explain the shallow upward migration of deep mud fluids in this central italy mud volcano the results can be used to identify the uprising of fluids with similar chemical physical properties even in areas where the superficial and morphological evidence of the volcanic bodies have been obliterated or covered

methane emission from mud volcanoes in eastern azerbaijan methane ch4 flux to the atmosphere was measured from gas vents and for the first time from soil microseepage at four quiescent mud volcanoes and one everlasting fire in eastern azerbaijan mud volcanoes show different activity of venting craters gryphons and bubbling pools with ch4 fluxes ranging from less than one to hundreds of tons per year microseepage ch4 flux is generally on the order of hundreds of milligrams per square meter per day even far away from the active centers the ch4 flux near the everlasting fires on the order of 105 mg m 2 d 1 represents the highest natural ch4 emission from soil ever measured the specific ch4 flux to the atmosphere between 102 and 103 t km 2 yr 1 was similar to specific flux from other mud volcanoes in europe at least 1400 tons of ch4 per year are released from the investigated areas it is conservatively estimated that all onshore mud volcanoes of azerbaijan during quiescent activity may still emit 0 3 0 9 106 t of ch4 per year into the atmosphere the new data fill a significant gap in the worldwide data set and confirm the importance of geologic sources of greenhouse ch4 although they are not yet considered in the climate study budgets of atmospheric ch4 sources and sinks

modelling eruption cycles and decay of mud volcanoes recent debates about the eruptive behavior of mud volcanoes and their activation mechanisms have been driven particularly by the lusi eruption in indonesia that resulted in huge commercial and cultural damages numerical modeling of mud volcanoes of which few exist can provide insight into eruptive behavior and contribute to hazard evaluation in this paper we present a simple model to describe fluid escape from an underground reservoir through a conduit extruded as a mud volcano at the surface the governing equations result in oscillatory behavior and we study the influence of changes in rheological properties of surrounding rock and fluid characteristics of the mud on extrusion dynamics we focus on understanding long term eruption behavior flow cycles and decay factors model results can be used to estimate the discharge rates and extruded volume from assumptions on the mud reservoir and conduit or conversely the reservoir or conduit properties from discharge rates

a composite mud volcano system in the chalk group of the north sea central graben abstract the study describes a large kilometre scale composite mud volcano system within the north sea chalk group containing both intrusion and extrusion features the upper part of the system consists of three stacked constructive components at the top a late palaeocene mound shaped extrusion with subtle onlaps is observed below a danian near surface intrusion caused forced folding of the c 100 m thick overburden this is underlain by a shallow intrusion the lower part of the mud volcano system is defined by a depletion related depression and the fluid conduit seismic data suggest that the source unit for the linked intrusion extrusion is to be found either within a lower cretaceous diapiric siliciclastic structure or within the fine grained carbonates of the chalk group the latter is more probable implying that chalk may generate hitherto undocumented intrusions and extrusions comparable with siliciclastic mud volcano systems remobilization is inferred to have been driven by fluidization caused by the influx of mainly pore water expelled from the lower cretaceous succession a distinct depositional variation within the chalk group caused early diagenetic differences in porosity preservation and mechanical properties of the chalk units allowing the remobilization of certain chalk units even at burial depths as great as 200 m

mud volcanism and fluid geochemistry in the cheleken peninsula western turkmenistan abstract a geological and geochemical study has been carried out to investigate the relationships between major mud volcano structures and deep fluid migration in the cheleken peninsula in the south caspian basin the fluid geochemistry allowed the origin and migration of the saline waters and the hydrocarbons to be deduced along with the regional source and reservoir rocks the emitted waters formed by the mixing of deep highly saline water from the main source rocks of the maykop fm with the caspian like pore water contained in the pliocene reservoirs the water composition is very similar to that emitted by the mud volcanoes in azerbaijan allowing comparisons to be done between the reservoirs in the western and eastern sides of the south caspian basin the associated oil is derived from a mixed type ii iii kerogen deposited in a sub oxic marine environment and generated during the early oil window the oil biomarkers indicate that the source rock is the maykop fm as previously determined for the other areas of the south caspian basin the spontaneous emissions showing different morphologies are mainly aligned along normal and transtensive fault systems which provide effective pathways for rapid fluid ascent from deep reservoirs to the surface

active mud volcanism observed with landsat 7 etm abstract mud volcanoes are relatively small spatter cones that erupt water laden mud and gases and occur throughout the world for many mud volcanoes the eruption of warm mud 10 40 c can be detected with high resolution thermal satellite imagery we demonstrate the utility of landsat 7 enhanced thematic mapper plus etm imagery for thermal monitoring of active mud volcanism we constrain the temperature and area of active mud discharge and estimate surface heat flux for two isolated mud volcanoes in the copper river basin alaska using band 6 10 4 12 5 m the heat flux results span a wide range due to uncertainties in the environmental conditions at the time of image acquisition but can be constrained to be less than 0 24 mw for each of the two mud volcanoes considering previously published field measurements with this higher resolution band 6 on the etm sensor as well as the high resolution thermal bands on the aster sensor reliable monitoring of mud volcanism on this scale is possible for the first time

subsurface combustion in mali refutation of the active volcanism hypothesis in west africa surface heat anomalies have been known in the timbuktu region in northern mali for more than a century since about 1960 several authors have argued that these heat anomalies are caused by incipient volcanic and hydrothermal activity surface temperatures as high as 765 c were measured locally in january 2002 and smoke emanated from holes and fractures in the ground we demonstrate that subsurface combustion of organic material is the source of the heat and the gases several square kilometers are currently active or have been affected by subsurface fires since 2001 self ignition during biological degradation of organic rich layers in the lacustrine deposits is the most likely mechanism that started the subsurface combustion that caused the heat anomalies in the area an important consequence of this conclusion is that west africa should still be regarded as volcanologically inactive and that possible reactivations of the major ew trending guinean nubian lineament are not associated with volcanism we suggest that the subsurface combustion in the timbuktu region today represents a phenomenon with a very long record in the trans saharan region

gaia s breath global methane exhalations abstract methane ch 4 is the most abundant organic compound in the earth s atmosphere where it acts as a greenhouse gas and thus has implications for global climate change the current atmospheric ch 4 budget however does not take into account geologically sourced ch 4 seepage geological sources of ch 4 include natural macro and micro seeps mud volcanoes and other miscellaneous sources such as gas hydrates magmatic volcanoes geothermal regions and mid ocean ridges macro seeps contribute 25 tg teragrams ch 4 yr to the atmosphere whereas micro seepage contributes perhaps 7 tg ch 4 yr mud volcanoes emit 5 tg ch 4 yr and miscellaneous sources emit 8 tg ch 4 yr to the atmosphere thus the total contribution to the atmosphere from geological sources is estimated to be 45 tg ch 4 yr which is significant to the atmospheric organic carbon cycle and should be included in any global inventory of atmospheric ch 4 we argue that the atmospheric ch 4 global inventory of the interplanetary panel on climate change must be adjusted in order to incorporate geologically sourced ch 4 from naturally occurring seepage