on the application of simple rift basin models to the south polar region of enceladus 1 the south polar terrain spt of saturn s moon enceladus is a mysteriously active region that exhibits intriguing tectonic signatures and widespread fracturing the central region of the nearly circular spt is depressed into the surface by a few hundred meters and bounded by a ring of cliffs roughly 1 km high in this study we investigate whether this depression and surrounding mountainous uplift is consistent with the morphology of terrestrial rift basins and the possibility that the spt could have formed during a tectonic event analogous to those of such rift basins on earth using three mechanical models of basin formation we compare our predicted topography of the spt with observed topography of the region the first of three models we consider assumes crustal stretching by factor b and predicts a basin depth of roughly 600 m closely matching previously published estimates of the depth at the spt models of extension and compression assuming an elastic response in the ice crust predict best fit mountain uplift of roughly 1820 m and 1130 m respectively our preferred model suggests that the icy shell in the spt has been stretched but the extension is partially balanced by compression along the edges of the basin leading to the uplift of the mountains along the boundary thereby implying that the spt may have a tectonic origin analogous to that of a terrestrial basin

the tolbachik volcanic massif a review of the petrology volcanology and eruption history prior to the 2012 2013 eruption abstract the primary goal of this paper is to summarize all of the published data on the tolbachik volcanic massif in order to provide a clear framework for the geochronologic petrologic geochemical and to a lesser extent the geophysical and tectonic characteristics of the tolbachik system established prior to the 2012 2013 eruption the tolbachik massif forms the southwestern part of the voluminous klyuchevskoy volcanic group in kamchatka the massif includes two large stratovolcanoes ostry sharp tolbachik and plosky flat tolbachik and a 70 km long zone of the basaltic monogenetic cones that form an arcuate rift like structure running across the plosky tolbachik summit the tolbachik massif gained international attention after the 1975 1976 great tolbachik fissure eruption gtfe which was one of the largest eruptions of the 20th century and one of the six largest basaltic fissure eruptions in historical time by the end of the gtfe 2 2 km 3 of volcanic products of variable basaltic compositions with morb like isotopic characteristics covered an area of 1000 km 2 during the following three decades more than 700 papers on various aspects of this eruption have been published both in national and international journals although the recent 2012 2013 eruption which is the main topic of this volume was not as long as the gtfe in duration or as large in area and volume of the erupted deposits it brought to the surface a unique volcanic material never found before in order to understand the data from new eruptions and make significant progress towards a better understanding of the tolbachik magmatic system it is important to be able to put the new results into the historic context of previous research

klyuchevskoy volcano kamchatka russia the role of high flux recharged tapped and fractionated magma chamber s in the genesis of high al2o3 from high mgo basalt

modelling albedo and specific balance of the greenland ice sheet calculations for the sondre stromfjord transect glacio meteorological data obtained during the greenland ice margin experiment gimex investigations in west greenland the sondre stromfjord transect have been used to test and calibrate four energy balance mass balance models for the ice snow surface the region is characterised by the development of a wide zone of low surface albedo in the course of the melting season this zone was simulated in one of the energy balance models by including the effect of surficial meltwater on albedo observed mass balance and albedo data were used to constrain the models although all the models are capable of predicting the transect balance reasonably well only the model with the meltwater albedo coupling is able to reproduce the observed albedo pattern and mass balance profile along the transect by including the feedback between surficial meltwater and albedo in the model the sensitivity of the specific balance to changes in air temperature is found to be greatest just below the equilibrium line in contrast to what is generally found for valley glaciers a 1 k warming of the air temperature would increase the mean ablation along the transect by 0 5 m w e year 1

comparison of enigmatic diamonds from the tolbachik arc volcano kamchatka and tibetan ophiolites assessing the role of contamination by synthetic materials abstract the enigmatic appearance of cuboctahedral diamonds in ophiolitic and arc volcanic rocks with morphology and infrared characteristics similar to synthetic diamonds that were grown from metal solvent requires a critical reappraisal we have studied 15 diamond crystals and fragments from tolbachik volcano lava flows using fourier transform infrared spectrometry ftir transmission electron microscopy tem synchrotron x ray fluorescence srxrf and laser ablation inductively coupled plasma mass spectrometry la icp ms ftir spectra of tolbachik diamonds correspond to typical type ib patterns of synthetic diamonds in tem films prepared using focused ion beam technique we find mn ni and mn si inclusions in tolbachik diamonds srxrf spectra indicate the presence of fe ni and fe ni mn inclusions with cr ti cu and zn impurities la icp ms data show variable but significantly elevated concentrations of mn fe ni and cu reaching up to 70 ppm these transition metal concentration levels are comparable with those determined by la icp ms for similar diamonds from tibetan ophiolites mn ni fe solvent was widely used to produce industrial synthetic diamonds in the former ussr and russia with very similar proportions of these metals hence it appears highly probable that the cuboctahedral diamonds recovered from kamchatka arc volcanic rocks represent contamination and are likely derived from drilling tools or other hard instruments kinetic data on diamond dissolution in basaltic magma or in fluid phase demonstrate that diamond does not form under the pressures and temperature conditions prevalent within the magmatic system beneath the modern day klyuchevskoy group of arc volcanoes we also considered reference data for inclusions in ophiolitic diamonds and compared them with the composition of solvent used in industrial diamond synthesis in china the similar inclusion chemistry close to ni70mn25co5 for ophiolitic and synthetic chinese diamonds scrutinized here suggests that most diamonds recovered from tibetan and other ophiolites are not natural but instead have a synthetic origin in order to mitigate further dubious reports of diamonds from unconventional tectonic settings and source rocks we propose a set of discrimination criteria to better distinguish natural cuboctahedral diamonds from those produced synthetically in industrial environments and found as contaminants in mantle and crust derived rocks

constraints on unrest in the tolbachik volcanic zone in kamchatka prior the 2012 13 flank fissure eruption of plosky tolbachik volcano from local seismicity and gps data abstract a new fissure eruption began on 27 november 2012 on the southern slope of plosky tolbachik volcano which is located in central kamchatka russia and is part of the klyuchevskoy volcano group we analyzed the displacement of the earth surface and the seismicity during several months before the eruption onset according to seismic and gps data the eruption was preceded by about 4 5 months july november 2012 of synchronous crustal deformation and seismicity the seismic anomaly comprises low energy level seismicity mainly m 1 2 2 3 under plosky tolbachik volcano at a depth of less than 5 km in the 2 3 weeks immediately preceding the eruption the rate of seismicity and the amount of radiated seismic energy exceeded the long term average values 2000 2011 by more than 40 times the deformation anomaly was recorded by displacement of the gps points at distances from 20 to 60 km to the north of tolbachik the principal axis of the compressive strain was approximately directed towards the tolbachik eruption site the permanent gps network detected radial compression and tangential stretching the compressive strain reached about 10 7 prior to eruption onset the comparable duration of seismic and deformation anomalies 4 5 months before the eruption is consistent with a common origin connected to magma rising from depth and is interpreted as indicating that they were medium term precursors to the eruption data recorded during this unrest episode of the tolbachik volcanic zone will contribute to understanding of the reawakening of volcanic activity in this region and others worldwide with similar characteristics

silicate sulfide liquid immiscibility in modern arc basalt tolbachik volcano kamchatka part i occurrence and compositions of sulfide melts abstract silicate sulfide liquid immiscibility plays a key role in the formation of magmatic sulfide ore deposits but incipient sulfide melts are rarely preserved in natural rocks this study presents the distribution and compositions of olivine hosted sulfide melt globules resulting from silicate sulfide liquid immiscibility in primitive arc basalts abundant sulfide droplets entrapped in olivine from primitive basalts of the 1941 eruption and pre historic eruptive cone mt 1004 of the tolbachik volcano kurile kamchatka arc inclusions range from submicron to 250 m in size coexist with sulfur rich glass 1 1 wt s and in some cases with magmatic anhydrite saturation in sulfide occurred early in the evolution of a water and sulfur rich magma moderately oxidized qfm 1 to 1 5 which crystallized high mg olivine fo86 92 clinopyroxene and cr spinel the process developed dense clouds of sulfide in relatively small volumes of magma with highly variable abundances of chalcophile metals the low degree of sulfide supersaturation promoted diffusive equilibration of the growing droplets with the melt in ni and cu resulting in high concentrations 38 mol of cus and nis in the earliest sulfide liquids the tolbachik samples provide a glimpse into deep arc processes not seen elsewhere and may show how arc magmas despite their oxidized nature saturate in sulfide

parameter uncertainty refreezing and surface energy balance modelling at austfonna ice cap svalbard 2004 08 we apply a physically based coupled surface energy balance and snowpack model to a site close to the equilibrium line on austfonna ice cap svalbard over the 2004 08 melt seasons to explain contributions to the energy available for melting and to quantify the significance of refreezing the model is forced using in situ meteorological measurements and precipitation downscaled from erainterim reanalysis applying a monte carlo approach to determine the tunable parameters of the model we estimate the uncertainty related to the choice of parameter values multiple criteria are evaluated to identify well performing parameter combinations evaluating the model performance with respect to longwave outgoing radiation snow and ice temperatures and surface displacement on average over the investigated melt seasons 1 june to 15 september net radiation and sensible heat contributed 90 2 and 10 2 respectively to the mean energy available for melting snow and ice the energy consumed by subsurface heat exchange reduced runoff by 15 2 in 2004 and 49 3 in 2008 refreezing of meltwater and rain was estimated to be 0 37 0 04mw e a 1on average over the five seasons which represents a considerable reduction of mass loss during summer our findings suggest that refreezing potentially exerts a decisive control on glacier mass balance in persistently snow or firncovered areas

on the role of subsurface heat conduction in glacier energy balance modelling we discuss the inclusion of the subsurface heat conduction flux into the calculation of the energy balance and ablation at the glacier atmosphere interface data from automatic weather stations are used to force an energy balance model at several locations on alpine glaciers and at one site in the dry andes of central chile the heat conduction flux is computed using a two layer scheme assuming that 36 of the net shortwave radiation is absorbed by the surface layer and that the rest penetrates into the snowpack we compare simulations conducted with and without subsurface heat flux results show that assuming a surface temperature of zero degrees leads to a larger overestimation of melt at the sites in the accumulation area 10 4 13 3 than in the ablation area 0 5 2 8 due to lower air temperatures and the presence of snow the difference between simulations with and without heat conduction is also high at the beginning and end of the ablation season up to 29 for the first 15 days of the season when air temperatures are lower and snow covers the glacier surface while they are of little importance during periods of sustained melt at all the locations investigated

a 210pb 226ra 230th 238u study of klyuchevskoy and bezymianny volcanoes kamchatka abstract lavas from klyuchevskoy and bezymianny volcanoes kamchatka appear to show a link between the extent of partial melting in their mantle source region and the subsequent degree of fractionation suffered by the magmas during passage through the crust this fractionation may have occurred on timescales significantly less than 1000 years if observed 226 ra excesses largely reflect variable residual porosity in the source melting region unlike most arc lavas those with the highest mgo contents and ba th ratios have the lowest 226 ra excess forward models suggest that those portions of the source which had undergone the greatest addition of u by fluids from the subducting plate also underwent the greatest extents of partial melting at the highest residual porosity at kluchevskoy a change from eruption of high mgo to high al 2 o 3 basaltic andesites around 1945 is reflected in an increase in size of 226 ra excess which seems to require a simultaneous decrease in residual porosity and suggests a rapid changes in the melting regime the eruption of andesites at bezyminanny simultaneous with the eruption of basaltic andesites at klyuchevskoy further suggests that different degree melts produced at differing residual porosity can be formed and extracted from the melt region at the same time thus the melting processes beneath klyuchevskoy and bezyminanny are demonstrably complex they have clearly been influenced by both fluid addition from the subducting plate and extension and decompression beneath the central kamchatka depression finally the 210 pb data are with one or two exceptions in equilibrium with 226 ra suggesting that there was restricted relative magma gas movement in this highly productive magmatic system

u th pa ra study of the kamchatka arc new constraints on the genesis of arc lavas abstract the 238u 230th 226ra and 235u 231pa disequilibria have been measured by mass spectrometry in historic lavas from the kamchatka arc the samples come from three closely located volcanoes in the central kamchatka depression ckd the most active region of subducted related volcanism in the world the large excesses of 226ra over 230th found in the ckd lavas are believed to be linked to slab dehydration moreover the samples show the uncommon feature of 230th 238u activity ratios both lower and higher than 1 the u series disequilibria are characterized by binary trends between activity ratios with 231pa 235u ratios all 1 it is shown that these correlations cannot be explained by a simple process involving a combination of slab dehydration and melting we suggest that they are more likely to reflect mixing between two end members a high magnesia basalt hmb end member with a clear slab fluid signature and a high alumina andesite haa end member reflecting the contribution of a slab derived melt the u th ra characteristics of the hmb end member can be explained either by a two step fluid addition with a time lag of 150 ka between each event or by continuous dehydration the inferred composition for the dehydrating slab is a phengite bearing eclogite equilibrium transport or dynamic melting can both account for 231pa excess over 235u in hmb end member nevertheless dynamic melting is preferred as equilibrium transport melting requires unrealistically high upwelling velocities to preserve fluid derived 226ra 230th a continuous flux melting model is also tested in this model 231pa 235u is quickly dominated by fluid addition and for realistic extents of melting this process cannot account for 231pa 235u ratios as high as 1 6 as observed in the hmb end member the involvement of a melt derived from the subducted oceanic crust is more likely for explaining the haa end member compositions than crustal assimilation melting of the oceanic crust is believed to occur in presence of residual phengite and rutile resulting in no 226ra 230th disequilibrium and low 231pa excess over 235u in the high alumina andesites consequently it appears that high alumina andesites and high magnesia basalts have distinct origins the former being derived from melting of the subducted oceanic crust and the latter from hydrated mantle it seems that there is no genetic link between these two magma types in contrast with what was previously believed

petrological and geochemical evolution of the tolbachik volcanic massif kamchatka russia abstract data on the geology petrography and geochemistry of middle late pleistocene rocks from the tolbachik volcanic massif kamchatka klyuchevskaya group of volcanoes are presented and compared with rocks from the neighboring mount povorotnaya klyuchevskaya group basement and holocene historical tolbachik monogenetic cones two volcanic series of lavas middle k and high k are found in the tolbachik massif the results of our data analysis and computer modeling of crystallization at different p t h 2 o fo 2 conditions allow us to reconstruct the geochemical history of the massif the tolbachik volcanic massif started to form earlier than 86 ka based on k ar dating during the formation of the pedestal and the lower parts of the stratovolcanoes the middle k melts depleted relative to nmorb fractionated in water rich conditions about 3 of h 2 o at the late pleistocene holocene boundary a large fissure zone was initiated and the geodynamical regime changed upwelling associated with intra arc rifting generated melting from the same mantle source that produced magmas more enriched in incompatible trace elements and subduction components these magmas are high k not depleted relative to n morb melts with island arc signatures and rift like characteristics the fissure opening caused degassing during magma ascent and the high k melts fractionated at anhydrous conditions these high k rocks contributed to the formation of the upper parts of stratovolcanoes at the beginning of holocene the high k rocks became prevalent and formed cinder cones and associated lava fields along the fissure zone however some features including 1975 1976 northern breakthrough are represented by middle k high mg rocks suggesting that both middle k and high k melts still exist in the tolbachik system our results show that fractional crystallization at different water conditions and a variably depleted upper mantle source are responsible for all observed variations in rocks within the tolbachik volcanic massif sr nd isotopes are consistent with 2 4 crustal assimilation during formation of the pedestal and stratovolcanoes while the young lava fields do not show evidence of crustal assimilation major and trace element data coupled with k ar dating provide strong evidence that mount povorotnaya located in 8 km northeast of plosky tolbachik is an old block of the tolbachik massif pedestal and for the moment it is the oldest 306 ka known object in klyuchevskaya group of volcanoes

the evolution of high alumina basalts of the klyuchevskoy volcano kamchatka russia based on microprobe analyses of mineral inclusions abstract the origin of calc alkaline high alumina basalts hab of the klyuchevskoy volcano kamchatka was examined using electron microprobe analyses of phenocrysts and mineral phases included in the phenocrysts continuous trends on major element variation diagrams suggest the hab were derived from high magnesia basalt hmb by fractional crystallization phenocrysts in the hab are strongly zoned olivine mg 91 64 clinopyroxene wo45 38en40 51fs5 20 and chrome spinel magnetite inclusions in them cr2o3 45 0 wt tio2 0 5 11 microprobe analyses of minerals included in the phenocrysts provide additional constraints on the mineral crystallization trends in the hab fe mg partitioning data when applied to the phenocrysts cores show they crystallized from a hmb the similarity of phenocryst core compositions in hab with those in hmb strongly suggests a genetic relationship between the two magma types

magma migration at the onset of the 2012 13 tolbachik eruption revealed by seismic amplitude ratio analysis abstract in contrast of the 1975 76 tolbachik eruption the 2012 13 tolbachik eruption was not preceded by any striking change in seismic activity by processing the klyuchevskoy volcano group seismic data with the seismic amplitude ratio analysis sara method we gain insights into the dynamics of magma movement prior to this important eruption a clear seismic migration within the seismic swarm started 20 hours before the reported eruption onset 05 15 utc 26 november 2012 this migration proceeded in different phases and ended when eruptive tremor corresponding to lava flows was recorded at 11 00 utc 27 november 2012 in order to get a first order approximation of the magma location we compare the calculated seismic intensity ratios with the theoretical ones as expected the observations suggest that the seismicity migrated toward the eruption location however we explain the pre eruptive observed ratios by a vertical migration under the northern slope of plosky tolbachik volcano followed by a lateral migration toward the eruptive vents another migration is also captured by this technique and coincides with a seismic swarm that started 16 20 km to the south of plosky tolbachik at 20 31 utc on november 28 and lasted for more than 2 days this seismic swarm is very similar to the seismicity preceding the 1975 76 tolbachik eruption and can be considered as a possible aborted eruption

phase relations and liquid lines of descent in hydrous ferrobasalt implications for the skaergaard intrusion and columbia river flood basalts crystallization experiments using a hydrous ferrobasalt as starting material conducted at 200mpa 940 12008c at a wide range of water activities 0 1 1 and redox conditions qfm 3 to qfm 4 where qfm is the quartz fayalite magnetite oxygen buffer show that h2o influences significantly the differentiation history of ferrobasaltic magmas a combination of our data with published experiments on dry ferrobasalt at 1atm provides an extensive experimental database for modeling and quantifying crystallization and differentiation processes within a typical fe rich tholeiitic system under both dry and hydrous conditions the addition of h2o decreases liquidus temperatures and changes significantly the proportions temperature range and sequence of crystallizing mineral phases the dry liquidus is at about 11708c whereas the liquidus for h2o saturated melts is at 10608c the main phases crystallizing from h2o bearing ferrobasalt at the investigated conditions are olivine ol clinopyroxene cpx plagioclase pl magnetite mt hematite hm ilmenite ilm and amphibole am the phase assemblage is similar to that of the dry system except for the presence of hm at extremely oxidizing conditions and am at low temperatures 59508c and h2o saturated conditions the important observation made in this study is that the stability of fe ti oxides and in particular mt as well as the simultaneous coprecipitation of mtand ilm are almost independent of the activity of h2o ah2o in the system whereas the liquidus temperatures of the silicate minerals are dramatically depressed by increasing ah2o the stabilities of oxides are controlled mainly by the redox conditions prevailing in the system the most pronounced effect of ah2o on the liquidus temperatures of silicates is observed for pl which shows a considerable delay in crystallization with progressive magma differentiation early crystallization of fe ti oxides in h2o bearing ferrobasaltic compositions precludes any significant fe enrichment during differentiation as fe enrichment is a characteristic feature of the skaergaard intrusion it implies that the skaergaard parental magma did not contain considerable amounts of water on the other hand our experiments indicate that the differentiation of some ferrobasaltic series from the columbia river flood basalt province might have occurred in magmatic systems containing significant amounts of volatiles 0 5 3 wt h2o

relationship between kamen volcano and the klyuchevskaya group of volcanoes kamchatka data on the geology petrography mineralogy and geochemistry of rocks from kamen volcano central kamchatka depression are presented and compared with rocks from the neighbouring active volcanoes the rocks from kamen and ploskie sopky volcanoes differ systematically in major elemental and mineral compositions and could not have been produced from the same primary melts the compositional trends of kamen stratovolcano lavas and dikes are clearly distinct from those of klyuchevskoy lavas in all major and trace element diagrams as well as in mineral composition however lavas of the monogenetic cones on the southwestern slope of kamen volcano are similar to the moderately high mg basalts from klyuchevskoy and may have been derived from the same primary melts this means that the monogenetic cones of kamen volcano represent the feeding magma for klyuchevskoy volcano rocks from kamen stratovolcano and bezymianny form a common trend on all major element diagrams indicating their genetic proximity this suggests that bezymianny volcano inherited the feeding magma system of extinct kamen volcano the observed geochemical diversity of rocks from the klyuchevskaya group of volcanoes can be explained as the result of both gradual depletion over time of the mantle n morb type source due to the intense previous magmatic events in this area and the addition of distinct fluids to this mantle source

the thermal conductivity of seasonal snow twenty seven studies on the thermal conductivity of snow k eff have been published since 1886 combined they comprise 354 values of k eff and have been used to derive over 13 regression equation and predicting k eff vs density due to large and largely undocumented differences in measurement methods and accuracy sample temperature and snow type it is not possible to know what part of the variability in this data set is the result of snow microstructure we present a new data set containing 488 measurements for which the temperature type and measurement accuracy are known a quadratic equation where is in g cm 3 and k eff is in w m 1 k 1 can be fit to the new data r 2 0 79 a logarithmic expression can also be used the first regression is better when estimating values beyond the limits of the data the second when estimating values for low density snow within the data set snow types resulting from kinetic growth show density independent behavior rounded grain and wind blown snow show strong density dependence the new data set has a higher mean value of density but a lower mean value of thermal conductivity than the old set this shift is attributed to differences in snow types and sample temperatures in the sets using both data sets we show that there are well defined limits to the geometric configurations that natural seasonal snow can take

calibrating a surface mass balance model for austfonna ice cap svalbard austfonna 8120 km 2 is by far the largest ice mass in the svalbard archipelago there is considerable uncertainty about its current state of balance and its possible response to climate change over the 2004 05 period we collected continuous meteorological data series from the ice cap performed mass balance measurements using a network of stakes distributed across the ice cap and mapped the distribution of snow accumulation using ground penetrating radar along several profile lines these data are used to drive and test a model of the surface mass balance the spatial accumulation pattern was derived from the snow depth profiles using regression techniques and ablation was calculated using a temperature index approach model parameters were calibrated using the available field data parameter calibration was complicated by the fact that different parameter combinations yield equally acceptable matches to the stake data while the resulting calculated net mass balance differs considerably testing model results against multiple criteria is an efficient method to cope with non uniqueness in doing so a range of different data and observations was compared to several different aspects of the model results we find a systematic underestimation of net balance for parameter combinations that predict observed ice ablation which suggests that refreezing processes play an important role to represent these effects in the model a simple pmax approach was included in its formulation used as a diagnostic tool the model suggests that the surface mass balance for the period 29 april 2004 to 23 april 2005 was negative 318 mm w e

magmatic plumbing systems of the monogenetic volcanic fields a case study of tolbachinsky dol kamchatka abstract clusters of small volume volcanoes that individually may be defined as monogenetic but have interlinked and interconnected plumbing systems are used to be categorized as monogenetic volcanic fields mvf we argue that such volcanic clusters should be distinguished as separate type of volcanism intermediate between monogenetic and polygenetic the magma plumbing system structure of the mvf its complexity and polymagmatic character is the key argument for the potential separation of them in a classification to avoid confusion caused by genetic meaning of the used words we suggest using a term areal volcanism or areal volcanic fields avf instead of mvf as defining this special type of volcanic activity here we provide a review of the main characteristic features of one of the largest holocene avf which is active now the tolbachik field of cinder cones in the southern part of klyuchevskaya volcano group kamchatka known in the literature as tolbachinsky dol this paper is focused on the research of magma plumbing system we consider structural morphological geological geochemical and petrological data on the erupted basalts and their genesis specially planned seismic experiments made in 2010 2015 seismic tomography and microseismic sounding allowed modeling of the principal elements of the magma plumbing system of tolbachik avf analysis of the investigations made in this area shows that tolbachik avf has a complex dynamic variable magmatic feeding system which can be visualized as a superposition of subvertical and sublateral magma conduits the contrast composition of the erupted rocks is caused by their different although genetically connected magma sources and mixing processes one of the long lived eruptive centers of tolbachik avf is plosky tolbachik stratovolcano which lost its independent activity and was captured by tolbachik avf in holocene the avf formed rejuvenated volcanism using the feeding system of the stratovolcano like an old anthill the magma plumbing system characteristics of tolbachinsky dol strongly support the idea of separation of avf from monogenetic volcanism type in the classification

a linear theory of orographic precipitation a linear theory of orographic precipitation is developed including airflow dynamics condensed water advection and downslope evaporation the formulation extends the widely used upslope model vertically integrated steady state governing equations for condensed water are solved using fourier transform techniques closed form expressions are derived for special cases for more general cases the precipitation field is computed quickly by multiplying the terrain transform by a wavenumber dependent transfer function five length scales are included in the model mountain width a buoyancy wave scale the moist layer depth and two condensed water advection distances the efficiency of precipitation in the model is sensitive to the decay of the forced ascent through the moist layer and to the advection of condensed water downwind into the region of descent the strong influence of horizontal scale on precipitation pattern and amount predicted by the model is discussed the model is illustrated by applying it to the olympic mountains in washington state

sector collapses and large landslides on late pleistocene holocene volcanoes in kamchatka russia on kamchatka detailed geologic and geomorphologic mapping of young volcanic terrains and observations on historical eruptions reveal that landslides of various scales from small 0 001 km3 to catastrophic up to 20 30 km3 are widespread moreover these processes are among the most effective and most rapid geomorphic agents of 30 recently active kamchatka volcanoes at least 18 have experienced sector collapses some of them repetitively the largest sector collapses identified so far on kamchatka volcanoes with volumes of 20 30 km3 of resulting debris avalanche deposits occurred at shiveluch and avachinsky volcanoes in the late pleistocene during the last 10 000 yr the most voluminous sector collapses have occurred on extinct kamen 4 6 km3 and active kambalny 5 10 km3 volcanoes the largest number of repetitive debris avalanches 10 during just the holocene has occurred at shiveluch volcano landslides from the volcanoes cut by ring faults of the large collapse calderas were ubiquitous large failures have happened on both mafic and silicic volcanoes mostly related to volcanic activity orientation of collapse craters is controlled by local tectonic stress fields rather than regional fault systems specific features of some debris avalanche deposits are toreva blocks huge almost intact fragments of volcanic edifices involved in the failure some have been erroneously mapped as individual volcanoes one of the largest toreva blocks is mt monastyr a 2 km3 piece of avachinsky somma involved in a major sector collapse 30 40 ka bp long term forecast of sector collapses on kliuchevskoi koriaksky young cone of avachinsky and some other volcanoes highlights the importance of closer studies of their structure and stability