geochemistry and zircon u pb geochronology of aligoodarz granitoid complex sanandaj sirjan zone iran the aligoodarz granitoid complex agc is located in the sanandaj sirjan zone ssz western iran and consists of quartz diorites granodiorites and subordinate granites whole rock major and trace element data mostly define linear trends on harker diagrams suggesting a cogenetic origin of the different rock types 87 sr 86 sr i and endt ratios are in the ranges 0 7074 0 7110 and 3 56 to 5 50 respectively the trace elements and sr nd isotopic composition suggest that the granitoids from the agc are similar to crustal derived i type granitoids of continental arcs the whole rock suite was produced by assimilation and fractional crystallization starting from a melt with intermediate composition likely possessing a mantle component in situ zircon u pb data on the granites with la icp ms yield a crystallization age of 165 ma inherited grains spanning in age from 180 ma up to 2027 ma were also found and confirm that assimilation of country rock has occurred chemical and chronological data on the agc were compared with those available for other granitoid complexes of the central ssz e g dehno boroujerd and alvand the comparison reveals that in spite of the different origins that have been proposed all these granitoid complexes are likely genetically related they share many chemical features and are derived from crustal melts with minor differences alvand granites have the most peculiar compositions most likely related to the presence of abundant pelitic component all these intrusions are coeval and reveal the presence of an extensive magmatic activity in the central sector of the ssz during middle jurassic

the anarak jandaq and posht e badam metamorphic complexes in central iran new geological data relationships and tectonic implications abstract the anarak jandaq and posht e badam metamorphic complexes occupy the nw part of the central east iranian microcontinent and are juxtaposed with the great kavir block and sanandaj sirjan zone our recent findings redefine the origin of these complexes so far attributed to the precambrian early paleozoic orogenic episodes and now directly related to the tectonic evolution of the paleo tethys ocean this tectonic evolution was initiated by late ordovician early devonian rifting events and terminated in the triassic by the eocimmerian collision event due to the docking of the cimmerian blocks with the asiatic turan block the variscan accretionary complex is a new name we proposed for the most widely distributed metamorphic rocks connected to the anarak and jandaq complexes this accretionary complex exposed from sw of jandaq to the anarak and kabudan areas is a thick and fine grain siliciclastic sequence accompanied by marginal sea ophiolitic remnants including gabbro basalts with a supra subduction geochemical signature new 40ar 39ar ages are obtained as 333 320 ma for the metamorphism of this sequence under greenschist to amphibolite facies moreover the limy intercalations in the volcano sedimentary part of this complex in godar e siah yielded upper devonian tournaisian conodonts the northeastern part of this complex in the jandaq area was intruded by 215 15 ma arc to collisional granite and pegmatites dated by id tims and its metamorphic rocks are characterized by some 40ar 39ar radiometric ages of 163 156 ma the variscan accretionary complex was northwardly accreted to the airekan granitic terrane dated at 549 15 ma later from the late carboniferous to triassic huge amounts of oceanic material were accreted to its southern side and penetrated by several seamounts such as the anarak and kabudan this new period of accretion is supported by the 280 230 ma 40ar 39ar ages for the anarak mild high pressure metamorphic rocks and a 262 ma u pb age for the trondhjemite rhyolite association of that area the triassic bayazeh flysch filled the foreland basin during the final closure of the paleo tethys ocean and was partly deposited and or thrusted onto the cimmerian yazd block the paleo tethys magmatic arc products have been well preserved in the late devonian carboniferous godar e siah intra arc deposits and the triassic nakhlak fore arc succession on the passive margin of the cimmerian block in the yazd region the nearly continuous upper paleozoic platform type deposition was totally interrupted during the middle to late triassic local erosion down to lower paleozoic levels may be related to flexural bulge erosion the platform was finally unconformably covered by liassic continental molassic deposits of the shemshak one of the extensional periods related to neo tethyan back arc rifting in late cretaceous time finally separated parts of the eocimmerian collisional domain from the eurasian turan domain the opening and closing of this new ocean characterized by the nain and sabzevar ophiolitic melanges finally transported the anarak jandaq composite terrane to central iran accompanied by large scale rotation of the central east iranian microcontinent ceim due to many similarities between the posht e badam metamorphic complex and the anarak jandaq composite terrane the former could be part of the latter if it was transported further south during tertiary time

characterization of volcanic thermal anomalies by means of sub pixel temperature distribution analysis the simultaneous solution of the planck equation involving the widely used dual band technique using two shortwave infrared swir bands allows for an estimate of the fractional area of the hottest part of an active lava flow f h and the background temperature of the cooler crust t c the use of a high spectral and spatial resolution imaging spectrometer with a wide dynamic range of 15 bits dais 7915 in the wavelength range from 0 501 to 12 67 m resulted in the identification of crustal temperature and fractional areas for an intra crater hot spot at mount etna italy this study indicates the existence of a relationship between these t c and f h extracted from dais and landsat tm data when the dual band equation system is performed on a lava flow a logarithmic distribution is obtained from a plot of the fractional area of the hottest temperature vs the temperature of the cooler crust an entirely different distribution is obtained over active degassing vents where increases in t c occur without any increase in f h this result indicates that we can use scatter plots of t c vs fh to discriminate between different types of volcanic activity in this case between degassing vents and lava flows using satellite thermal data

cooling history of the chapedony metamorphic core complex central iran implications for the eurasia arabia collision abstract new apatite and zircon u th he thermochronometry is used to constrain the late stage cooling history of the chapedony metamorphic core complex in the saghand region of central iran providing new constraints on the cenozoic tectonic evolution of this segment of the euro arabian collision zone zircon and apatite he ages from the footwall indicate that it cooled to near surface temperatures by 30 ma combined with previous high temperature thermochronology the new data require that the chapedony metamorphic core complex cooled from 750 c to 60 c in less than 20 million years at 80 c myr cooling of the complex occurred through tectonic exhumation at a rate of 1 2 1 5 km myr exhumation of the core complex occurred during the main phase of subduction of the distal arabian margin beneath the central iranian plate at 49 to 30 ma zircon he ages from the hangingwall units of the complex suggest an earlier pulse of exhumation in middle late cretaceous apatite he ages from the hangingwall 22 30 ma are significantly younger than the core complex exhumation but is consistent with the regional timing of initial eurasia arabia collision

geochronology of high grade metamorphic rocks from the anjul area lut block eastern iran abstract u pb and rb sr geochronology has been used to constrain robust ages for leucosomes and high grade gneisses from the anjul area in the eastern part of the lut block iran the new results do not support the previously suggested proterozoic age for this occurrence but instead reveal the importance of jurassic and cretaceous magmatic and or metamorphic processes ionprobe u pb zircon dating yielded four age groups 200 168 120 and 110 ma textural observations suggest that ages 200 ma represent inherited zircons the majority of zircons yielded jurassic 168 2 and 169 2 ma and cretaceous 120 3 108 2 111 3 ma intercept ages explanations for the two dominant age groups 168 and 110 ma include the following alternatives a the jurassic ages constrain the protolith age of magmatic precursors that experienced metamorphic overprinting at 110 ma and b both the 168 ma and 110 ma ages indicate the time of metamorphic episodes e g zircon formation during different anatectic events or migmatization followed by a lower temperature overprint associated with new zircon growth multi point rb sr mineral isochrons of three additional gneisses indicated ages of 102 3 ma 102 1 ma and 97 2 ma these ages further document the importance of cretaceous metamorphism in the anjul area the difference compared to the u pb ages of zircon overgrowths is interpreted to indicate cooling after a thermal event with or without partial melting the two major occurrences of metamorphic rocks in the eastern lut block are exposed in the deh salm and the anjul region these occurrences may represent two different segments of a single metamorphic belt that can broadly be related to accretionary and or collisional processes induced by convergence between the afro arabian and eurasian plates our geochronological study provides a conclusive evidence for cretaceous metamorphism we speculate that zircon overgrowths with cretaceous ages reflect metamorphic processes unrelated to melt formation that overprinted a pre existing population recording jurassic anatexis

temperature of an active lava channel from spectral measurements kilauea volcano hawaii a narrow band spectroradiometer was used to determine the characteristic temperatures of a very active channeled lava flow for the phase 50 eruption of pu u o o on the east rift zone of kilauea volcano hawaii during the twilight of 19 february 1992 14 spectra of this activity were acquired over a 51 minute interval 18 29 to 19 20 hawaiian standard time hst from which the thermal distribution of energy of two 18 m2 areas one near the center and one near the margin of the flow may be investigated a twocomponent thermal mixing model applied to the data taken of the center of the channel gave in the most powerful instance 1 8x105 w m2 a crust temperature of 940 c a hot component temperature of 1120 c and a hot radiating area of 60 of the total area a simultaneous spectrum acquired near the channeled flow margin yielded a crust temperature of 586 c and a hot area of only 1 2 of the total area radiating at 1130 c average radiant flux densities recorded for the center of the lava channel 1 3x105 w m2 average are much greater than previous measurements of lava lakes 4 9x103 w m2 or recently emplaced lava flows maximum of 7 2x104 w m2 the energetic nature of this eruption is shown by satellite measurements made at 02 33 hst on 22 february 1992 by the advanced very high resolution radiometer in band 2 0 72 1 10 m these show the utility of using existing satellites with moderate resolution 1 km x 1 km pixels and high temporal coverage eight overpasses each day for hawaii as potential thermal alarms for rapidly assessing the hazard potential of large volcanic eruptions

time series analysis of effusive volcanic activity using the ers along track scanning radiometer the 1995 eruption of fernandina volcano galapagos islands abstract the ers 1 along track scanning radiometer atsr provides frequent shortwave and longwave infrared radiance data of every terrestrial volcanic region at a spatial resolution of 1 km 2 by adopting a simplified model that assumes that any observed active lava flow is composed of two distinct thermal components we present techniques that allow subpixel lava flow areas to be estimated from the atsr spectral radiance data such estimates are especially useful in documenting effusive volcanic activity occurring in remote regions where ground observations may be sparse or completely lacking we use a time series atsr dataset to document the 1995 eruption of fernandina volcano an important but isolated volcanic island in the galapagos archipelago we estimate that in 1995 fernandina produced a 6 km 2 lava flow field with a volume of around 20 million m 3 a similar magnitude to previously studied fernandina eruptions this is the first time series analysis of an active galapagos lava flow produced using remotely sensed data previous fernandina flows have been investigated many months or years after the activity had ceased the current and future availability of frequent low spatial resolution infra red radiance data from spaceborne sensors such as the advanced along track scanning radiometer aatsr and the moderate resolution imaging spectrometer modis should ensure that adaptations of these techniques can be used to document future volcanic eruptions occuring in similarly isolated regions

cooling rate of an active hawaiian lava flow from nighttime spectroradiometer measurements a narrow band spectroradiometer has been used to make nighttime measurements of the phase 50 eruption of pu u o o on the east rift zone of kilauea volcano hawaii on february 19 1992 a ger spectroradiometer was used to determine the cooling rate of an active lava flow this instrument collects 12 bit data between 0 35 to 3 0 m at a spectral resolution of 1 5 nm thirteen spectra of a single area on a pahoehoe flow field were collected over a 59 minute period 21 27 22 26 hst from which the cooling of the lava surface has been investigated a two component thermal mixing model flynn 1992 applied to data for the flow immediately on emplacement gave a best fit crustal temperature of 768 c a hot component at 1150 c and a hot radiating area of 3 6 of the total area over a 52 minute period within the time interval between flow resurfacings the lava flow crust cooled by 358 c to 410 c at a rate that was as high as 15 c min 1 our observations have significance both for satellite observations of active volcanoes and for numerical models of the cooling of lava flows during their emplacement

overview of tectonic settings related to the rifting and opening of mesozoic ocean basins in the eastern tethys oman himalayas and eastern mediterranean regions

multispectral thermal infrared mapping of the 1 october 1988 kupaianaha flow field kilauea volcano hawaii multispectral thermal infrared radiance measurements of the kupaianaha flow field were acquired with the nasa airborne thermal infrared multispectral scanner tims on the morning of 1 october 1988 the tims data were used to map both the temperature and emissivity of the surface of the flow field the temperature map depicted the underground storage and transport of lava the presence of molten lava in a tube or tumulus resulted in surface temperatures that were at least 10 c above ambient the temperature map also clearly defined the boundaries of hydrothermal plumes which resulted from the entry of lava into the ocean the emissivity map revealed the boundaries between individual flow units within the kupaianaha field in general the emissivity of the flows varied systematically with age but the relationship between age and emissivity was not unique distinct spectral anomalies indicative of silica rich surface materials were mapped near fumaroles and ocean entry sites this apparent enrichment in silica may have resulted from an acid induced leaching of cations from the surfaces of glassy flows such incipient alteration may have been the cause for virtually all of the emissivity variations observed on the flow field the spectral anomalies representing areas where the acid attack was most intense

strike slip kinematics in central and eastern iran estimating fault slip rates averaged over the holocene 1 according to gps measurements the right lateral shear between central iran and afghan blocks amounts to 16 mm yr a model based on very long term estimates of fault rates suggests the current shear originated about 5 ma ago and has been accommodated by strike slip faulting limited to the western 2 mm yr gowk nayband fault and eastern 14 mm yr sistan system fault edges of the lut block we have used high resolution spot5 pixel size 2 5 m images to measure recent cumulative offsets and estimate slip rates over shorter time periods that average several seismic cycles only recent offsets a few tens of meters have been found along the anar fault inside the central iran plateau and along the sistan faults east of the lut the offset morphologies postdate the last incision of the network and are most probably of holocene age 12 2 ka the corresponding slip rates range between 0 5 0 75 mm yr 1 75 2 5 mm yr 1 5 mm yr 1 2 5 mm yr for the anar east neh west neh and asagie fault respectively these estimates suggest the gps shear rate across the lut may not extrapolate over the holocene they also indicate strike slip faulting is not confined to the lut edges but also occurs in central iran suggesting the ongoing strike slip tectonics might have originated between 8 and 22 ma ago earlier than considered previously and consistent with observations in ne iran

first recorded eruption of mount belinda volcano montagu island south sandwich islands the modvolc satellite monitoring system has revealed the first recorded eruption of mount belinda volcano on montagu island in the remote south sandwich islands here we present some initial qualitative observations gleaned from a collection of satellite imagery covering the eruption including modis landsat 7 etm aster and radarsat 1 data modvolc thermal alerts indicate that the eruption started sometime between 12 september and 20 october 2001 with low intensity subaerial explosive activity from the island s summit peak mount belinda by january 2002 a small lava flow had been emplaced near the summit and activity subsequently increased to some of the highest observed levels in august 2002 observations from passing ships in february and march 2003 provided the first visual confirmation of the eruption aster images obtained in august 2003 show that the eruption at mount belinda entered a new phase around this time with fresh lava effusion into the surrounding icefield modis radiance trends also suggest that the overall activity level increased significantly after july 2003 thermal anomalies continued to be observed in modis imagery in early 2004 indicating a prolonged low intensity eruption and the likely establishment of a persistent summit lava lake similar to that observed on neighboring saunders island in 2001 our new observations also indicate that lava lake activity continues on saunders island

ephemeral grounding as a signal of ice shelf change interferometric synthetic aperture radar insar observations of ice shelf tidal deformation reveal the wide transition between grounded and floating ice as well as local areas where the ice shelf is only grounded at low tide a condition that we call ephemeral grounding ephemeral grounding creates a subtle local disturbance on the vertical motion field of the ice shelf surface in response to changes in occanic tide which is detected with millimetric precision using insar these ice shelf features are however not expected to produce a noticeable disturbance on the ice shelf velocity field to illustrate the influence of ephemeral grounding on ice shelf creep flow we use a finite element model in which ephemeral grounding is incorporated through a variable basal friction coefficient the results show that while ice rises permanently grounded areas have a pronounced influence on the ice shelf velocity field areas of ephemeral grounding have a vanishingly small influence what is thus of most interest is the capacity for observations of ephemeral grounding to reveal subtle changes in ice shelf thickness over time we discuss an example in the thwaites glacier area west antarctica where multi year data show how ice rises become ephemeral grounding and subsequently disappear this result is consistent with the grounding line retreat and ice thinning of thwaites glacier

plate tectonic evolution of the southern margin of eurasia in the mesozoic and cenozoic abstract thirteen time interval maps were constructed which depict the triassic to neogene plate tectonic configuration paleogeography and general lithofacies of the southern margin of eurasia the aim of this paper is to provide an outline of the geodynamic evolution and position of the major tectonic elements of the area within a global framework the hercynian orogeny was completed by the collision of gondwana and laurussia whereas the tethys ocean formed the embayment between the eurasian and gondwanian branches of pangea during late triassic early jurassic times several microplates were sutured to the eurasian margin closing the paleotethys ocean a jurassic cretaceous north dipping subduction boundary was developed along this new continental margin south of the pontides transcaucasus and iranian plates the subduction zone trench pulling effect caused rifting creating the back arc basin of the greater caucasus proto south caspian sea which achieved its maximum width during the late cretaceous in the western tethys separation of eurasia from gondwana resulted in the formation of the ligurian penninic pieniny magura ocean alpine tethys as an extension of middle atlantic system and a part of the pangean breakup tectonic system during late jurassic early cretaceous times the outer carpathian rift developed the opening of the western black sea occurred by rifting and drifting of the western central pontides away from the moesian and scythian platforms of eurasia during the early cretaceous cenomanian the latest cretaceous paleogene was the time of the closure of the ligurian pieniny ocean adria alcapa terranes continued their northward movement during eocene early miocene times their oblique collision with the north european plate led to the development of the accretionary wedge of the outer carpathians and its foreland basin the formation of the west carpathian thrusts was completed by the miocene the thrust front was still propagating eastwards in the eastern carpathians during the late cretaceous the lesser caucasus sanandaj sirjan and makran plates were sutured to the iranian afghanistan plates in the caucasus caspian sea area a north dipping subduction zone jumped during paleogene to the scythian turan platform the shatski terrane moved northward closing the greater caucasus basin and opening the eastern black sea the south caspian underwent reorganization during oligocene neogene times the southwestern part of the south caspian basin was reopened while the northwestern part was gradually reduced in size the collision of india and the lut plate with eurasia caused the deformation of central asia and created a system of nw se wrench faults the remnants of jurassic cretaceous back arc systems oceanic and attenuated crust as well as tertiary oceanic and attenuated crust were locked between adjacent continental plates and orogenic systems

surface temperature measurements of active lava flows on kilauea volcano hawai i systematic hand held radiometer measurements of lava surface temperatures in active flows and tubes on kilauea volcano hawai i reveal complexities that cannot be resolved in remotely sensed data from aircraft or satellites using portable infrared minolta land cyclops radiometers we measured surface temperatures of flows at various distances from their sources and investigated cooling rates and the development of crust our measurements suggest that the upper surface of these lava flows can be split into a minimum of four thermal components core 1050 c visco elastic skin 750 900 c rigid solid crust 750 c and flow margins 175 c for the a a flows investigated a cool rigid crust characteristically developed in the central part of channels within 30 m of the source vent and incandescent lava was exposed in the marginal shear zones of channels this affects the heat loss and morphology of lava in active channels our investigations of temperature distributions on pahoehoe flow fields reveal temperature anomalies of up to 150 c above active tubes and tumuli

the 16 september 1986 eruption of lascar volcano north chile satellite investigations landsat thematic mapper tm images acquired in 1984 and 1985 revealed a pronounced thermal anomaly on lascar volcano north chile subsequent images showed that the anomaly was persistent but variable and that after a significant eruption on 16 september 1986 it was weaker and divided into several sources tm studies and other observations of lascar indicate that the persistent thermal anomaly may be due to high temperature fumaroles within the summit crater goes weather satellite images and field investigations confirm that the 16 september event was a short lived vulcanian type eruption which produced an ash column that reached 15 km altitude the ash cloud can be tracked on geos images to about 400 km downwind and covered an area 112 000 km2 transport occurred in the upper troposphere at speeds up to 180 km h ash fall from the plume was well sorted and moderately fine grained md 200 m formation and fallout of ash as aggregates was unimportant in the deposition of the ash layer although small the lascar 16 september eruption is significant because few historic eruptions have been recorded in the central andes little would have been known of the eruption in the absence of remote sensed data

active tectonics and late cenozoic strain distribution in central and eastern iran 1 right lateral shear between central iran and afghanistan is accommodated on n s right lateral strike slip faults surrounding the aseismic dasht e lut north of 34 n the right lateral shear is accommodated on left lateral faults that rotate clockwise about vertical axes little is known of the late tertiary and younger offsets and slip rates on the active fault systems results that are important for understanding the regional tectonics we use observations from satellite imagery to identify displaced geological and geomorphological markers which we use in conjunction with the overall morphology and orientation of the active fault systems to estimate the total cumulative right lateral shear estimates of cumulative fault movements from offset features and inferred vertical axis rotation of fault bounded blocks suggest that the late cenozoic strain is concentrated toward the eastern margin of iran along the sistan shear zone where bedrock offsets of at least 70 km are observed across the active faults the geomorphology of the deh shir anar and great kavir strike slip faults in central iran suggest that although little shortening is accommodated across this region they might still be active and hence capable of producing earthquakes present day activity on these faults in central iran would not be expected from distributions of instrumental and historical earthquakes although speculative the late tertiary strain distribution described in this paper is consistent with what we know of the present day rates of shear in eastern iran and provides a framework to which later more detailed work can be added

thermal radiance observations of an active lava flow during the june 1984 eruption of mount etna the thermal budget of an active lava flow observed on 20 june 1984 from the southeast crater of mount etna sicily italy was analyzed from data taken by the landsat thematic mapper the thematic mapper images constitute one of the few satellite data sets of sufficient spatial and spectral resolution to allow calibrated measurements on the distribution and intensity of thermal radiation from active lava flows using radiance data from two reflective infrared channels we can estimate the temperature and areas of the hottest parts of the active flow which correspond to hot 500 c fractures or zones at the flow surface using this technique we estimate that only 10 20 of the total radiated thermal power output is emitted by hot zones or fractures which constitute less than 1 of the observed surface area generally it seems that only where hot fractures or zones constitute greater than about 1 of the surface area of the flow will losses from such features significantly reduce internal flow temperatures using our radiance observations as boundary conditions for a multicomponent thermal model of flow interior temperature we infer that for the parts of this flow subject to analysis the boundary layer and flow thickness effects dominate over radiant zones in controlling the depression of core temperature

building the zagros collisional orogen timing strain distribution and the dynamics of arabia eurasia plate convergence he zagros mountains are the result of the arabia eurasia collision initiated at 35 ma as the rifted arabian lithosphere was underthrusted beneath the iranian plate due to its negative buoyancy the onset of crustal thickening started at 25 ma as recorded by the hinterland exhumation and foreland clastic deposition deformation throughout the arabia eurasia collision zone and the uplift of the iranian plateau occurred after 15 12 ma as a result of shortening thickening of the thin iranian crust we emphasize that only 42 of the post 35 ma convergence is partitioned by shortening within central iran tomographic constraints show ongoing slab steepening or breakoff in the nw zagros whereas underthrusting of the arabian plate is observed beneath central zagros the current subduction dynamics can be explained by the original lateral difference in the buoyancy of the distal margin that promoted slab sinking in nw zagros and underthrusting in central zagros critical wedge approach applied to the zagros favors the hypothesis of strong brittle crust detached above a viscous lower crust in contrast the weak sedimentary cover deforms by buckling of a thick multilayered cover thrust faulting associated with folding occurs in the competent layers and is responsible for most of the earthquakes there is evidence that the role of the slab pull force in driving the arabian plate motion was reduced after 12 ma large scale mantle flow induced by mantle upwelling at the afar plume appears to be the main driver of the arabia plate motion we stress that the main kinematic change in the zagros region occurred at 15 12 ma as the zagros uplifted before the arabian slab detached the zagros appears key to investigate coupling between continental rheology plate driving forces and mountain building in which the role of rift inheritance appears to be central

volcano monitoring using short wavelength infrared data from satellites data from remote sensing satellites operating in the short wavelength infrared can be used to measure temperatures of about 150 c and above the gain settings of the landsat thematic mapper tm sensors are such that to record pixel integrated temperatures from 150 c to over 1000 c requires the use of several spectral bands if the radiant source occupies less than a whole pixel as is the case for fumaroles or a crusted lava surface with incandescent cracks then the pixel integrated temperature is less than the actual surface temperature of the hot areas and appears to be different at each wavelength by determining pixel integrated temperature in two spectral bands we can estimate both the temperature and size of hot areas which occupy less than a complete pixel in some cases our observations provide the only available data on the state of activity of a particular volcano in others they support and refine field observations our landsat tm data reveal otherwise unobserved precursor and subsequent activity related to the september 1986 eruption of lascar volcano chile and supplement other data on the march 1986 eruption of augustine volcano alaska they also indicate the continued presence of lava lakes at erta ale ethiopia in the absence of any ground based observations and document minor eruptive activity at mount erebus antarctica landsat multispectral scanner data have been used to measure the variation in temperature along a lava flow on sierra negra galapagos islands which occurred in 1979

magmatic and metamorphic history of the deh salm metamorphic complex eastern lut block eastern iran from u pb geochronology the deh salm metamorphic complex dmc of the lut block in east iran consists of metapelites amphibolites marbles and metasandstones intruded by granite and pegmatites u pb dating of zircon monazite xenotime and titanite by id tims show that the granitic rocks were emplaced at 166 163 ma confirming that the high temperature metamorphism was synchronous with the intrusive activity and that the region cooled rapidly thereafter late to post magmatic hydrothermal activity was probably responsible for the late crystallization at 159 5 ma of zircon and titanite in an amphibolite and of monazite in granite xenocrystic zircons yield indications for a carboniferous component in the source together with a variety of precambrian ages which indicate a provenance of the sedimentary protolith from mature continental crust the timing and rapidity of the events are consistent with evolution of the dmc in a back arc environment during the jurassic subduction of the neotethys ocean

strategies insights and the recent advances in volcanic monitoring and mapping with data from nasa s earth observing system in 1991 the u s national aeronautics and space administration nasa launched a comprehensive program to study the earth as one environmental system now called the earth science enterprise ese this coordinated monitoring effort was initially comprised of free flying satellites and space shuttle missions as well as airborne and ground based studies the satellite component of the ese is known as the earth observing system eos which has now entered a planned long term global monitoring phase the first eos satellite terra was launched in december of 1999 and offers integrated measurements of numerous solid earth and atmospheric processes including volcanic activity there are currently 10 nasa eos designated satellites carrying over thirty instruments all of which are providing integrated measurements of the interactions between the earth s global cycles included in this effort are science investigations that examine the solid earth cycle and the natural hazards that are an inevitable result of that cycle for volcanologists the new higher spatial spectral and temporal resolution eos data have spawned a variety of new algorithms and methodologies to monitor changes in volcanic activity map volcanic surfaces and investigate volcanic processes thermal anomaly detection plume chemistry and mass flux lava composition and textural properties interaction of ash with the natural and human environment and mitigation of hazards are but a few of the topics being addressed with these data sets in this paper we summarize the current state of volcanic remote sensing in the new eos era and introduce the more detailed papers that follow in this special issue this work stems from a special session at the fall 2001 american geophysical union agu meeting that was convened to showcase the current research in volcanic systems and processes using the new eos satellite data sets that session was also intended to provide a forum for field aircraft and other satellite validated observations of volcanic edifices and processes our aim in this special issue is to focus on a series of detailed examples where the authors have used eos data to investigate a specific question rather than a generalized overview of all possible volcanological applications of remote sensing data d 2004 elsevier b v all rights reserved

magnetic fabrics and microstructures of the jurassic shah kuh granite pluton lut block eastern iran and geodynamic inference abstract the jurassic shah kuh granite pluton was emplaced in the northeastern part of the lut block eastern iran while this block was a part of the active margin under which the tethys ocean that separated arabia from central iran was subducting since this time the lut block has rotated and migrated northward up to its present position this structural study of the shah kuh aims at strengthening the evidence of its original geodynamical location thanks to a systematic collection of oriented samples in the field well defined fabric and microstructural patterns were deduced from magnetic fabric measurements and optical microscopy observations the overall magnetic fabric of the pluton yields vertical north south striking foliations and shallow lineations plunging to the north the corresponding microstructures attest to their formation in the magmatic stage i e during emplacement subsequent deformation characterized by sub mylonitic microstructures has modified the original fabric into a northwest and locally a west northwest trend inside a two kilometre wide corridor this corridor reflects the trace of a sinistral shear zone that offsets the previous north south magmatic pattern of the pluton the latter magmatic pattern is proposed to result from the shear component of strain that was parallel to the ancient active margin during pluton emplacement as a result of strain partitioning a situation frequently documented at convergent margins sinistral shear along an e w directed south facing active margin assuming a northeastward slip vector for the tethys ocean during the jurassic and accepting a 150 counterclockwise rotation of the lut block after emplacement of the shah kuh pluton best explains both the magmatic and the solid state lineation patterns

convergence history across zagros iran constraints from collisional and earlier deformation the zagros orogen provides a unique opportunity within the alpine system to evaluate the interplay between a young tertiary collision and earlier subduction obduction processes within the crush zone and the sanandaj sirjan internal zone separating the zagros fold belt from central iran we document several major tectonic events taking place at the end of the cretaceous of the eocene and from the mio pliocene onwards ca 20 15 ma contrary to recent interpretations our data cross sections and description of the overall deformation style strongly suggest that the main zagros thrust mzt is deeply rooted possibly to moho depths and that the suture zone effectively runs along the mzt field observations show that the final resorption of the oceanic domain took place slightly after 35 ma and that collision must have started before ca 23 25 ma in northern zagros the shortening rate across the crush zone since the mid miocene 20 15 ma is estimated at a minimum 3 4 mm year shear movements in the crush zone during the eocene oligocene period and extensional strike slip movements in the internal zones during the late cretaceous point to an oblique setting early in the convergence history a geotectonic scenario for convergence from the time of obduction to the present is finally proposed

chronology of the episode 54 eruption at kilauea volcano hawaii from goes 9 satellite data the free availability of goes satellite data every 15 minutes makes these data an attractive tool for studying short term changes on cloud free volcanoes in the pacific basin we use cloud free goes 9 data to investigate the chronology of the january 1997 episode 54 eruption of kilauea volcano hawaii seventy six images for this effusive eruption were collected over a 60 hour period and show the opening and shutdown of active fissures the draining and refilling of the pu u o o lava lake and the cessation of activity at the ocean entry

thin skinned deformation near shahdad southeast iran abstract kilometre scale subparallel folds in the nw se trending shahdad fold and thrust belt show active thin skinned deformation produced by late pliocene quaternary compressional tectonics between the yazd and lut blocks of the central microcontinent of southeast iran the shahdad fold and thrust belt developed in a miocene quaternary sedimentary sequence with gypsiferous marl overlain by well stratified gypsiferous siltstone sandstone and conglomerate the geometry of the fold and thrust belt is shown in four regional cross sections which demonstrate common fault propagation folds developed above thrusts splays and associated with curving ridges in the northeast incipient thrusts and back thrusts have developed at the tip of the blind northeast dying out sole thrust however further west a major back thrust has brought to the surface the lower part of the stratigraphic succession malakhordeh thrust in some fault related folds parts of the folds have been eroded and syntectonic sedimentary strata containing younger gypsiferous conglomerates have been deposited over an unconformity surface these younger layers are also flexed above the underlying fault propagation fold as the result of renewed slippage along the active fault collapsing has developed in the hinge zones of these folds the sole detachment fault has developed through the lower plastic gypsiferous marls near their contact with the underlying paleocene eocene volcanic rocks of the lut block

effects of viewing geometry on avhrr observations of volcanic thermal anomalies abstract we investigate the influence of viewing geometry and dynamic range of the advanced very high resolution radiometer avhrr sensor on detecting eruptions on poorly monitored volcanoes numerical models of sunwarmed flows and typical active features associated with hawaiian eruptions overturning lava lakes surface flows of three different sizes and lava tubes with skylights show that new lava flows at 1000 c can be identified at all scan angles if the area of the activity exceeds 60 m 2 given a background temperature of 20 c more difficult is the detection of small breakouts of lava flows or tube fed flows when these features lie towards the edge of the swath because of the dynamic range and gain setting of the sensor bands 3 4 and 5 saturate at 49 c it is possible that similar thermal signatures may be produced when inactive flows are heated by the sun the ability of the avhrr to detect on going activity in hawaii in july 1991 is tested by comparing landsat thematic mapper and nadir avhrr scenes obtained within 3 5 hours of each other for an active pahoehoe flow field with a well developed tube system this comparison shows that within the area of thermally alarmed avhrr pixels

lava flow thermal analysis using three infrared bands of remote sensing imagery a study case from mount etna 2001 eruption abstract infrared remotely sensed data can be used to estimate heat flux and thermal features of active volcanoes the model proposed by crisp and baloga crisp j baloga s 1990 a model for lava flows with two thermal components journal of geophysical research 95 1255 1270 for active lava flows considers the thermal flux a function of the fractional area of two thermally distinct radiant surfaces the larger surface area corresponds to the cooler crust of the flow the smaller one to fractures in the crust in this model the crust temperature t c the temperature of the cracks t h and the fractional area of the hottest component f h represent the three unknowns to work out the simultaneous solution of the planck equation dual band technique for two distinct shortwave infrared swir bands allows to estimate any two of the parameters t c t h f h if the third is assumed dozier j 1981 a method for satellite identification of surface temperature fields of subpixel resolution remote sensing environment 11 221 229 the airborne sensor mivis was flown on mount etna during the july august 2001 eruption this hyperspectral imaging spectrometer offers 72 bands in the swir range and 10 bands in thermal infrared tir region of the spectrum which can be used to solve the dual band system without any assumptions therefore we can combine three spectral mivis bands to obtain simultaneous solutions for the three unknowns here the procedure for solving such a system is presented it is then demonstrated that a tir channel is required to better pinpoint solutions to the 2 components model finally the spatial and statistical characteristic of the resultant mivis derived temperature and flux distributions are introduced and statistics for each hot spot investigated

assumptions in the evaluation of lava effusion rates from heat radiation 1 the availability of high resolution thermal imagery of active lava flows has stimulated the use of radiance maps for the evaluation of lava effusion rates this is made possible by simple formulae relating the lava flow rate to the energy radiated per unit time from the planimetric surface of the flow such formulae are based on a specific flow model and consequently their validity is subject to the model assumptions an analysis of these assumptions reveals that the current use of the formulae is not consistent with the model the reason why they provide reasonable although very rough values for effusion rates appears to be that the actual radiated energy is controlled by a feature the nonuniform temperature of flow surface which is not accounted for by the model and which counterbalances the effect of inconsistent use of the formulae

anatomy of 1986 augustine volcano eruptions as recorded by multispectral image processing of digital avhrr weather satellite data eighteen digital avhrr advanced very high resolution radiometer data sets from noaa 6 and noaa 9 polar orbiting satellites recorded between 27 march and 7 april 1986 depict the eruptive activity of augustine volcano located 280 km sw of anchorage alaska the synoptic view resolution of either 1 1 or 4 4 km frequent coverage often twice a day and multispectral coverage five bands 0 58 0 68 0 72 1 1 3 55 3 93 10 5 11 3 and 11 5 12 5 m makes the avhrr broadly applicable to analyzing explosive eruption clouds the small scale of the augustine activity column heights of 2 13 km and eruption rates of 2x106 8x107 metric tonnes day facilitated intensive multispectral study because the plumes generally covered areas within the 550x550 km area of one easily manipulated image field hourly ground weather data and twice daily radiosonde measurements from stations surrounding the volcano plus numerous volcanological observations were made throughout the eruption providing important ground truth with which to calibrate the satellite data the total erupted volume is estimated to be at least 0 102 km3 the pattern of changing eruption rates determined by satellite observations generally correlate with more detailed estimates of explosion magnitudes multispectral processing techniques were used to distinguish eruption clouds from meteorological clouds variable weather during the augustine eruption offered an opportunity to test various trial algorithms a ratio between thermal ir channels four and five served to delineate the ashbearing eruption plumes from ordinary clouds future work is needed to determine whether the successful multispectral discrimination is caused by wavelength dependent variable emission of silicate ash or reflects a spectral role of sulfuric acid aerosol in the plume

a chronology of the 1991 to 1993 mount etna eruption using advanced very high resolution radiometer data implications for real time thermal volcano monitoring between december 1991 and march 1993 a continuous effusive eruption at mount etna built a 7 6 km2 lava flow field flows extended to within 1 km of the town of zafferana before a successful artificial diversion was carried out higher up the volcano during this eruption the spaceborne advanced very high resolution radiometer avhrr acquired 308 images on which the activity could be detected since these data can be freely and directly available such coverage potentially allows regular real time monitoring ground observations and a flow map that we produced using a spot image and electronic distance measurement allowed us to develop and test data extraction techniques avhrr radiance maps were consistent with known locations of surface activity these documented the transition from channel to tube fed phases the changing threat to zafferana and flow diversion quantitative analysis of the avhrr data enabled estimation of active lava area thermal flux effusion rates and total flow field volume our estimates for eruption rate and total flow field volume 5 6 to 7 6 m3 s and 220 106 to 300 106 m3 respectively are in agreement with published ground based estimates of 5 8 m3 s and 235 106 m3 these correlations demonstrate the high degree of confidence that can now be placed in interpretations of avhrr time series for eruptions where ground based data are scanty

cretaceous tertiary convergence and continental collision sanandaj sirjan zone western iran abstract the sanandaj sirjan zone contains the metamorphic core of the zagros continental collision zone in western iran the zone has been subdivided into the following from southwest to northeast an outer belt of imbricate thrust slices radiolarite bisotun ophiolite and marginal sub zones which consist of mesozoic deep marine sediments shallow marine carbonates oceanic crust and volcanic arc respectively and an inner complexly deformed sub zone late palaeozoic mesozoic passive margin succession rifting and sea floor spreading of tethys occurred in the permian to triassic but in the sanandaj sirjan zone extension related successions are mainly of late triassic age subduction of tethyan sea floor in the late jurassic to cretaceous produced deformation metamorphism and unconformities in the marginal and complexly deformed sub zones deformation climaxed in the late cretaceous when a major southwest vergent fold belt formed associated with greenschist facies metamorphism and post dated by abundant palaeogene granitic plutons in the southwest of the zone a late cretaceous island arc passive margin collision occurred with ophiolite emplacement onto the northern arabian margin similar to that in oman final closure of tethys was not completed until the miocene when central iran collided with the northeast arabian margin

low cost volcano surveillance from space case studies from etna krafla cerro negro fogo lascar and erebus satellite data offer a means of supplementing ground based monitoring during volcanic eruptions especially at times or locations where ground based monitoring is difficult being directly and freely available several times a day data from the advanced very high resolution radiometer avhrr offers great potential for near real time monitoring of all volcanoes across large 3000 3000 km areas herein we describe techniques to detect and locate activity estimate lava area thermal flux effusion rates and cumulative volume and distinguish types of activity application is demonstrated using data for active lavas at krafla etna fogo cerro negro and erebus a pyroclastic flow at lascar and open vent systems at etna and stromboli automated near real time analysis of avhrr data could be achieved at existing or cheap to install receiving stations offering a supplement to conventional monitoring methods