paraglacial rock slope stability glaciation and deglaciation along with their associated climatic and non climatic processes modify slope stresses and influence slope stability paraglacial slope failures are those that are a part of or influenced by the transition from glacial conditions to non glacial conditions gravitational failure of rock slopes is a primary and dominant process of slope evolution in mountainous terrain and is the subject of this paper which 1 reviews the approaches taken for researching paraglacial rock slope failure patterns and processes 2 summarises the spatial and temporal patterns of post glacial failures 3 assesses the factors influencing slope stability during glaciation and deglaciation 4 explores some of the applications of paraglacial research and 5 highlights some of the outstanding issues to be resolved and provides recommendations for terminology relating to paraglacial slope processes

seismoelectromagnetic effect associated with the izmit earthquake and its aftershocks in order to investigate the resistivity structure beneath the northern and the southern branches of the western part of the north anatolian fault zone nafz which has been known as a seismic gap area we started wideband magnetotelluric mt measurements on 27 july 1999 along a north south profile crossing the northern branch near izmit and the southern branch near iznik when the izmit kocaeli earthquake m w 7 4 occurred on 17 august 1999 mt fields were being measured at five sites four of which happened to be located near the surface rupture zone associated with the mainshock and large variations in the mt fields were observed in association with seismic waves we propose motional electromagnetic induction in the electrically conducting crust which vibrates under the earth s magnetic field as one of the possible generation mechanisms for such mt field variations for more detailed studies of such a mechanism we installed a wideband mt instrument and a three component seismometer at two of the four sites on 16 september 1999 and made simultaneous measurements during several aftershocks the estimate of the order of the magnitude of motional electromagnetic response derived from the mt fields and ground motion observed during a large aftershock m 4 5 supports our claim that the seismo dynamo effect is a plausible mechanism for variations in the mt fields associated with the seismic waves manuscript received 31 july 2000

remotely sensed debris thickness mapping of bara shigri glacier indian himalaya despite the important role of supraglacial debris in ablation knowledge of debris thickness on himalayan glaciers is sparse a recently developed method based on reanalysis data and thermal band satellite imagery has proved to be potentially suitable for debris thickness estimation without the need for detailed field data in this study we further develop the method and discuss possibilities and limitations arising from its application to a glacier in the himalaya with scarce in situ data surface temperature patterns are consistent for 13 scenes of advanced spaceborne thermal emission and reflection radiometer aster and landsat 7 imagery and correlate well with incoming shortwave radiation and air temperature we use an energy balance approach to subtract these radiation or air temperature effects in order to estimate debris thickness patterns as a function of surface temperature both incoming shortwave and longwave radiation are estimated with reasonable accuracy when applying parameterizations and reanalysis data however the model likely underestimates debris thickness probably due to incorrect representation of vertical debris temperature profiles the rate of heat storage and turbulent sensible heat flux moreover the uncertainty of the result was found to increase significantly with thicker debris a promising result since ablation is enhanced by thin debris of 1 2 cm

improved models of the piezomagnetic field for the 2011 mw 9 0 tohoku oki earthquake abstract to assess the feasibility of observing changes in the magnetic field produced by the piezomagnetic effect an improved model of the piezomagnetic field corresponding to the mw 9 0 tohoku oki earthquake is presented in contrast to an earlier study the proposed model explicitly considers the spatial distribution of slip on the seismic fault and the results from this new model differ significantly from those of the previous model where slip distributions were ignored quantitative aspects of the piezomagnetic effect are discussed through comparisons of data and models one feature clarified is that because the fault rupture is so far offshore the expected amplitudes are quite small at onshore existing observation sites consequently there would have been little chance of observing sizable piezomagnetic signals at inland sites during the tohoku oki earthquake nevertheless piezomagnetic signals were reportedly detected at a few sites possibly indicating that the stress sensitivity or the initial magnetization was larger by several factors than assumed on the other hand relatively large variations in the magnetic field of up to 10 nt may have occurred offshore this means that if ocean bottom sensors had been installed larger piezomagnetic signals would have been detected moreover the piezomagnetic field in offshore areas is sensitive to the detailed slip distribution suggesting that observations of the magnetic field at ocean bottom sites might provide important constraints on determination of slip models

seismomagnetic observation during the 8 july 1986 magnitude 5 9 north palm springs earthquake a differentially connected array of 24 proton magnetometers has operated along the san andreas fault since 1976 seismomagnetic offsets of 1 2 and 0 3 nanotesla were observed at epicentral distances of 3 and 9 kilometers respectively after the 8 july 1986 magnitude 5 9 north palm springs earthquake these seismomagnetic observation are the first obtained of this elusive but long anticipated effect the data are consistent with a seismomagnetic model of the earthquake for which right lateral rupture of 20 centimeters is assumed on a 16 kilometer segment of the banning fault between the depths of 3 and 10 kilometers in a region with average magnetization of 1 ampere per meter alternative explanations in terms of electrokinetic effects and earthquake generated electrostatic charge redistribution seem unlikely because the changes are permanent and complete within a 20 minute period

geomagnetic changes associated with the dike intrusion during the 2000 miyakejima eruptive activity japan abstract a marked magnetic field change exceeding 200 nt was detected by a three component magnetometer at the beginning of the 2000 miyakejima eruptive activity the change in the magnetic field is correlated with an earthquake activity and crustal deformation which indicate a dike intrusion very close to the observation site a dike model based on the crustal deformation data shows that the primary cause of the magnetic change was the piezomagnetic effect associated with the dike emplacement and that the other potential factors including thermal and electrokinetic effects were unlikely to be its principal cause we obtained a new dike model by combining both the crustal deformation and the magnetic field change which is sensitive to the strong stress changes near the edges of dike the new dike model shows lateral and upward propagation of the dike during its intrusion and suggests that shallow cracks induced by the dike intrusion near the ground surface contributed to the changes seen in the magnetic field

a regional inventory of rock glaciers and protalus ramparts in the central italian alps abstract we present a regional inventory of rock glaciers n 1514 and protalus ramparts 228 for the lombardy region central italian alps to identify and classify the landforms we inspect three sequential air orthophoto mosaics and a 2 m dsm and conduct confirmatory field work the inventory forms an empirical basis to analyze i the relative contribution of hillslope i e talus slopes and glacial i e moraines sediment stores to rock glacier sediment supply ii linkages between the landforms inventoried and local topographic attributes iii the spatial variability of periglacial activity in relation to a parsimonious set of environmental variables i e elevation precipitation and lithology and iv the effects of the pleistocene holocene climatic transition on the distribution of intact and relict landforms this analysis reveals that the elevation of rock glacier termini can vary over 200 m as a function of slope aspect in turn the distribution of rock glaciers among aspect categories is controlled by the structure of the valley network that promotes nw and se exposures talus rock glaciers prevail numerically over the glacier related typology even though the latter population appears to have increased during the holocene relict and intact rock glaciers have distinct spatial patterns in that the former display on average a 400 m elevation drop and a less clustered distribution towards northern aspects suggesting that they have developed in more permafrost prone climatic conditions analyzing the study region through a 27 5 km grid has been instrumental for showing that the rock glacier specific area and terminus elevation are i positively correlated with terrain elevation and ii negatively correlated with mean annual precipitation as a consequence in relation to holocene generalized atmospheric temperature rise intact rock glaciers have progressively disappeared from the wetter and milder portions of the central italian alps analysis of rock glacier occurrence across litho tectonic sectors does not provide conclusive dependences and requires further analysis this inventory which represents a necessary preliminary step for modelling the spatial distribution of discontinuous permafrost at the regional scale fills a critical geographic gap in the context of ongoing permafrost research in the european alps e g permanet

rock glacier dynamics stick slip motion coupled to hydrology 1 we demonstrate an approach to simulate rock glacier dynamics based on a three dimensional stick slip model coupled to a simple model of melt water dispersion simulation results account for observed kinematic discontinuities and exhibit a distribution of slip event sizes that is characterized by large fluctuations following a power law the model presents a feedback loop of dynamics and internal structure 1 the evolution of shear horizons which are correlated to melt water occurrence can be seen and 2 melt water distribution narrows to regions of maximum slip although this approach is promising improvements in some details must be made the solution for stress transfer accompanying slip has been taken from a model of a sheared body that is vertically constrained in future models the boundary conditions must be modified to that of a body confined only at its base additionally a heuristic treatment of hydrology currently used must be further quantified

magnetic field observations in the near field the 28 june 1992 mw 7 3 landers california earthquake recent reports suggest that large magnetic field changes occur prior to and during large earthquakes two continuously operating proton magne tometers lsbm and ochm at distances of 17 3 and 24 2 km respectively from the epicenter of the 28 june 1992 mw 7 3 landers earthquake recorded data through the earthquake and its aftershocks these two stations are part of a differentially connected array of proton magnetometers that has been operated along the san andreas fault since 1976 the instruments have a sensitivity of 0 25 nt or better and transmit data every 10 min through the goes satellite to the usgs headquarters in menlo park california seismomagnetic offsets of 1 2 0 6 and 0 7 0 7 nt were observed at these sites in comparison offsets of 0 3 0 2 and 1 3 0 2 nt were observed during the 8 july 1986 mt 5 9 north palm springs earthquake which occurred directly beneath the ochm magnetometer site the observations are generally consistent with seismomagnetic models of the earthquake in which fault geometry and slip have the same form as that determined by either inversion of the seismic data or inversion of geodetically determined ground displacements produced by the earthquake in these models right lateral rupture occurs on connected fault seg ments in a homogeneous medium with average magnetization of 2 a m the fault slip distribution has roughly the same form as the observed surface rupture and the total moment release is 1 1 1020 nm there is no indication of dif fusion like character to the magnetic field offsets that might indicate these ef fects result from fluid flow phenomena it thus seems unlikely that these earth quake generated offsets and those produced by the north palm springs earthquake were generated by electrokinetic effects also there are no indications of en hanced low frequency magnetic noise before the earthquake at frequencies be low 0 001 hz

early electromagnetic waves from earthquake rupturing i theoretical formulations yongxin gao 1 2 xiaofei chen 1 2 hengshan hu3 and jie zhang1 2 1school of earth and space sciences university of science and technology of china hefei 230026 china e mail gaoyongxin1982 yahoo com cn 2laboratory of seismology and physics of earth s interior university of science and technology of china hefei 230026 china 3department of astronautics and mechanics harbin institute of technology harbin 150001 china

rockglacier activity studies on a regional scale comparison of geomorphological mapping and photogrammetric monitoring in their spatial distribution as well as in their different states of activity rockglaciers imply important information on former and recent permafrost conditions two different methods were applied in one study area turtmann valley swiss alps in order to compare their suitability in assessing rockglacier activity the comparison of geomorphological mapping and photogrammetric monitoring demonstrated a good accordance especially on a regional scale on a local scale some differences in delimitation of the landforms as well as in the degree of activity were found one reason for the observed differences is the qualitative character of geomorphological mapping resulting from the variable suitability of single parameters and combinations thereof in the determination of rockglacier activity based on these results geomorphological mapping of rockglaciers can be improved by data from photogrammetric monitoring therefore at best the two methods are combined when analysing former and present permafrost distribution copyright 2007 john wiley sons ltd

himalayan glacial sedimentary environments a framework for reconstructing and dating the former extent of glaciers in high mountains abstract reconstructing paleoenvironmental change from glacial geologic evidence in the himalayas has been difficult because of the lack of organic material for radiocarbon dating and the problems of correctly identifying the origin of highly dissected landforms studies of the contemporary glacial depositional environments and ancient landforms and sediments in the hunza valley karakoram mountains the lahul and garhwal himalaya and the khumbu himalaya illustrate the variability in processes landforms and sediment types these studies can be used to interpret ancient landforms and sediments for paleoenvironmental reconstructions and aid in forming strategies for sampling sediments and rocks for the developing techniques of cosmogenic radionuclide crn surface exposure and optically stimulated luminescence osl dating many himalayan glaciers have thick covers of supraglacial debris derived from valley sides and such debris mantled glaciers exhibit important differences from clean glaciers both in terms of debris transport processes and the depositional landforms that they produce analysis of sediment landform associations can be used to reconstruct processes of sediment transport and deposition and the relationship between moraines and other landforms and climatic forcing cycles such analysis is of fundamental importance in guiding sampling and interpretation in crn and osl dating work

volcanomagnetic changes accompanying the onset of the 2002 2003 eruption of mt etna italy abstract remarkable changes in the local magnetic field were associated with the onset of the 2002 2003 flank eruption at mt etna after differential magnetic field measurements were filtered from the external noise by using adaptive filters we recognized two stages in the total intensity changes which are closely related to different volcanic events a rapid variations of about 4 5 nt associated with october 26 seismic swarm recorded beneath the summit craters b step like variations of 9 10 nt coincident with october 27 eruptive fissures opening up in the north flank these observations are generally consistent with those calculated from simple magnetic models of these volcanic processes in which the magnetic changes are generated by stress redistribution due to magmatic intrusions at different depth the magnetic data not only allow the timing of the intrusive event to be described in greater detail but also together with other volcanological and geophysical evidences permit some constraints to be set on the characteristics of propagation of a shallow dike firstly at around midnight on 26 october magma was rapidly injected to a depth of 3 4 km just below the summit craters secondly after 1 00 on 27 october continued intrusion magma occurred upward and culminated a few hundred meters below the free surface fractured along a n e direction thirdly at about 2 28 magma gave rise to an explosive fissural vent at the northern base of the ne crater near 3000 m a s l finally at about 5 00 the first eruptive fissure became active along the eastern border of the ne rift at 2500 m a s l the rate of growth of the magnetic anomalies moreover leads to the interpretation that the magmatic intrusion travelled northward from base of the ne crater to the ne rift at approximately 14 m min

rock glaciers and the geomorphological evolution of deglacierizing mountains abstract rock glaciers are an important geomorphic element of glaciated mountain landscapes but our understanding of their distribution and ages controls on their development and their importance in regional mountain hydrology and mountain geomorphic evolution is incomplete in part this incomplete knowledge arises through problems associated with identifying rock glaciers on a morphological basis alone amplified by the multiple ways in which rock glaciers can form in different glacial periglacial and paraglacial settings this study focuses on rock glaciers as a paraglacial mountain landscape element and considers the relationships between rock glaciers and glacial periglacial and paraglacial processes new geomorphic and sedimentary data on different rock glaciers from the khumbu region of nepal are presented these data show that even within a single region rock glaciers may have varied origins and thus likely ages and different climatic and environmental controls we argue that rock glaciers in deglacierizing mountains may have a long residence time in the landscape unlike many other glacially influenced mountain landforms and can undergo significant morphodynamic changes as glaciated landscapes transition into paraglacial landscapes

direct magnetic signals from earthquake rupturing iwate miyagi earthquake of m 7 2 japan abstract the key point of this paper is that for the first time we successfully observed co rupturing earth s magnetic field changes due to the piezomagnetic effect caused by earthquake rupturing electromagnetic changes associated with earthquakes have been investigated previously most of them are coseismic step like offsets in the geomagnetic field which are regarded as the piezomagnetic effect caused by the total static stress changes resulting from an earthquake proton precession magnetometers have so far been mainly used to detect seismomagnetic effects for which the measurement interval was usually 1 or 10 min and the measurement accuracy was 0 1 nt for seismomagnetic observations we employed flux gate magnetometers whose specifications are the measurement with accuracy of 0 01 nt and with the sampling interval of 0 5 or 1 s by virtue of such highly sensitive magnetometers we show observations of magnetic signals accompanying fault movement our observation site happened to be situated at an epicentral distance of 26 km from the 2008 iwate miyagi nairiku earthquake of m 7 2 in ne japan magnetic field components began to change almost simultaneously with the onset of the earthquake rupture and grew non linearly until the first p wave arrival such magnetic signals are most probably generated by the changing stress field due to rupturing i e the piezomagnetic effect rather than the seismic dynamo effect or electromagnetic induction within the conducting crust because they lack oscillatory features like seismic waves we attempt to interpret the observations with the aid of quasi static piezomagnetic model calculation which strongly supported our observation results

rock glacier dynamics in marginal periglacial environments vertical electric sounding bottom temperature of winter snowcover bts and ground thermal measurement debris surface analysis and a differential global positioning system dgps survey were performed on the posets rock glacier pyrenees between 2001 and 2008 high precision records of horizontal and vertical movements of the rock glacier were measured using a dgps on ten steel rods total and annual average displacements and thickness changes for each control point were derived from the field survey horizontal and vertical displacement rates in different sectors of the rock glacier were compared and these compared with thermal structural and morphological maps the inferred surface deformation was characterized by extensional and compressive flows in which two dynamic types were found the first type of movement is defined by the slide and flows related to the existence of an ice body over the frost body the second dynamic type involved the displacement generated by deformation of the frozen body the study attempts to understand the surface movement and dynamics of rock glaciers in marginal cold environments and their usefulness as environmental geoindicators copyright 2010 john wiley sons ltd

mass transport by active rockglaciers in the khumbu himalaya abstract this paper investigates the talus transport and geomorphic work accomplished by active rockglaciers in the khumbu himalaya nepal active rockglaciers are responsible for a considerable amount of horizontal and vertical sediment movement in this area rates of sediment displacement are in the order of 7 1 106 m t yr 1 km 2 the most effective mechanism of sediment transport however is a debris covered glacier with rates of 1 2 107 m t yr 1 km 2 a comparison with geomorphic work accomplished by active rockglaciers in the swiss alps shows that geomorphic effectiveness exceeds the one determined in the khumbu himalaya rockglaciers debris covered glaciers and rockfall amount to a total of geomorphic work two orders of magnitude higher than similar phenomena in the rocky mountains of colorado active tectonics recent glacier activity and climatic conditions specific to this region are possible explanations for this difference

current transition from glacial to periglacial processes in the dolomites south eastern alps abstract a close relationship between glacial and periglacial landforms is frequently observed in alpine environments where a transition from glacial to periglacial processes often took place after the end of the little ice age lia understanding the origin of these landforms is challenging and assessing the current spatial domain of glacial and periglacial processes may be a difficult task in high relief areas where thick and widespread debris cover often characterize rapidly decaying glaciers here we present a comprehensive study of a composite landform located in the dolomites south eastern alps combining geomorphological geophysical and topographic surveys with ground surface temperature measurements results indicate that a debris covered glacier persists in the upper part rather large compared to the lia extent but currently inactive and rapidly losing mass an active rock glacier exists in the lower part surrounded by discontinuous permafrost a frozen body about 10 m thick was detected in the rock glacier and geomorphological evidence suggests that this ice mass is completely detached from the debris covered glacier our findings suggest that the lower part of the composite landform is probably a remnant of the ancient glacier tongue and is currently evolving under periglacial conditions periglacial processes are therefore replacing glacial processes which dominated in this site during the lia

modelling the feedbacks between mass balance ice flow and debris transport to predict the response to climate change of debris covered glaciers in the himalaya many himalayan glaciers are characterised in their lower reaches by a rock debris layer this debris insulates the glacier surface from atmospheric warming and complicates the response to climate change compared to glaciers with clean ice surfaces debris covered glaciers can persist well below the altitude that would be sustainable for clean ice glaciers resulting in much longer timescales of mass loss and meltwater production the properties and evolution of supraglacial debris present a considerable challenge to understanding future glacier change existing approaches to predicting variations in glacier volume and meltwater production rely on numerical models that represent the processes governing glaciers with clean ice surfaces and yield conflicting results we developed a numerical model that couples the flow of ice and debris and includes important feedbacks between debris accumulation and glacier mass balance to investigate the impact of debris transport on the response of a glacier to recent and future climate change we applied this model to a large debris covered himalayan glacier khumbu glacier in nepal our results demonstrate that supraglacial debris prolongs the response of the glacier to warming and causes lowering of the glacier surface in situ concealing the magnitude of mass loss when compared with estimates based on glacierised area since the little ice age khumbu glacier has lost 34 of its volume while its area has reduced by only 6 we predict a decrease in glacier volume of 8 10 by ad2100 accompanied by dynamic and physical detachment of the debris covered tongue from the active glacier within the next 150 yr this detachment will accelerate rates of glacier decay and similar changes are likely for other debris covered glaciers in the himalaya

rock glacier nomenclature a re assessment several contentious issues have arisen from rock glacier nomenclature for example whether the term rock glacier implies genesis from glacial ice or genesis from permafrost the situation is compounded since rock glacier classification may be based on several different parameters some of which are measured and quantified others inferred these include gross morphology dynamics processes of formation location internal characteristics thermal regime and age uncertainties in specifying the genesis in the light of the potential complexity means that definitions should be related to recognisable topographic forms which allow mapping of such features the distinction is made between rock glaciers sensu stricto which follows the original descriptions and typology of the early years of the 20th century and protalus lobes the forms can usually be differentiated in terms of length breadth ratios as well as by their relative locations some of the most common issues of contention within rock glacier research can be solved by this approach

a history of pacific northwest earthquakes recorded in holocene sediments from lake washington large earthquakes can trigger slumping of the steep walls of lake basins and landslides in the drainage area resulting in turbidite deposition in the lake and increased detrital flux from inlets holocene sediments in piston cores from lake washington contain a series of terrigenous layers that were episodically deposited in the lake sedimentological geochemical and paleomagnetic analyses on nine piston cores show that the detrital layers are temporally and areally correlatable indicating basinwide disruptions these layers are opaque on x radiographs are coincident with magnetic susceptibility peaks have abundant aluminosilicate minerals are relatively coarse grained and have low organic carbon and biogenic silica contents the thicknesses and geographic distributions of the layers suggest that they are not due to floods or delta destabilization side scan swath imagery and subbottom profiling show that large slumps subaqueous landslides and debris flows are common along the margins of the lake a detailed chronology established from 21 radiocarbon ages on five cores show that a prominent turbidite was deposited about 1000 1100 years ago this turbidite apparently was triggered by a large earthquake that probably occurred on the seattle fault other depositional events in the sediment record at 1500 1700 2400 2500 and 2800 3200 years ago coincide with periods of landsliding that have been previously inferred from the dating of drowned trees in the lake more than 30 depositional events have occurred in the last 12 000 years and 21 disturbances have occurred since the deposition of the mazama ash about 7 600 years ago if all the events are due to earthquakes the puget sound region has been subject to major shaking every 300 to 400 years the strong intensities needed to trigger subaqueous slides may not be generated by just local sources such as the seattle fault but could also be caused by great subduction earthquakes occurring along the coast

relationship between seismic electric signals and tectonics derived from dense geoelectric observations in taiwan some researchers have suggested that significant electromagnetic changes that can be detected prior to strong earthquakes are associated with the tectonics and subsurface structures beneath monitoring stations numerical simulation seems to support this phenomenon however to date few field measurement data are available to address this issue in this work we used the shifting correlation method to analyze 2 month recordings of 20 geoelectric stations in taiwan and found at least two stations had recorded geoelectric signals significantly correlated with known seismic events these two stations are installed on large reverse faults which are probably characterized by high stress concentrations before earthquakes in addition they share the same resistivity variation pattern namely a conductor layer sandwiched between two high resistivity layers moreover both stations are above the electrical resistivity boundaries which means they have an increased probability of recording the abnormal disturbance once em signals have been emitted from eqs our analysis results support the viewpoint that lateral and vertical electrical resistivity variation and conductors in the subsurface may be able to amplify seismic electric signals

seismomagnetic effects from the long awaited 28 september 2004 m 6 0 parkfield earthquake precise measurements of local magnetic fields have been obtained with a differentially connected array of seven synchronized proton magnetometers located along 60 km of the locked to creeping transition region of the san andreas fault at parkfield california since 1976 the m 6 0 parkfield earthquake on 28 september 2004 occurred within this array and generated coseismic magnetic field changes of between 0 2 and 0 5 nt at five sites in the network no preseismic magnetic field changes exceeding background noise levels are apparent in the magnetic data during the month week and days before the earthquake or expected in light of the absence of measurable precursive deformation seismicity or pore pressure changes obser vations of electric and magnetic fields from 0 01 to 20 hz are also made at one site near the end of the earthquake rupture and corrected for common mode signals from the ionosphere magnetosphere using a second site some 115 km to the northwest along the fault these magnetic data show no indications of unusual noise before the earthquake in the ulf band 0 01 20 hz as suggested may have preceded the 1989 ml 7 1 loma prieta earthquake nor do we see electric field changes similar to those suggested to occur before earthquakes of this magnitude from data in greece uni form and variable slip piezomagnetic models of the earthquake derived from strain displacement and seismic data generate magnetic field perturbations that are con sistent with those observed by the magnetometer array a higher rate of longer term magnetic field change consistent with increased loading in the region is apparent since 1993 this accompanied an increased rate of secular shear strain observed on a two color edm network and a small network of borehole tensor strainmeters and increased seismicity dominated by three m 4 5 5 earthquakes roughly a year apart in 1992 1993 and 1994 models incorporating all of these data indicate increased slip at depth in the region and this may have played a role in the final occurrence of the 28 september 2004 m 6 0 parkfield earthquake the absence of electric and magnetic field precursors for this and other earthquakes with m 5 7 3 elsewhere in the san andreas fault system indicates useful prediction of damaging earthquakes seems unlikely using these electromagnetic data

reconstructing the transport history of glacigenic sediments a new approach based on the co variance of clast form indices abstract two indices are used to describe the aggregate shape and roundness characteristics of glacially transported clasts the c40 index the percentage of clasts with c a ratios 0 4 and the ra index the percentage of very angular and angular clasts in a sample analysis of the between and within sample co variance of these indices provides a powerful tool for discriminating actively and passively transported clasts in glacigenic deposits use of these indices is illustrated in an analysis of the form characteristics of clasts from lateral and frontal moraines at storbreen jotunheimen these fall between those of actively transported clasts in basal till low c40 and ra values and those of unmodified frost weathered clasts high c40 and ra values both indices decline down moraine within sample analyses of clast shape demonstrates that these aggregate clast form gradients reflect changes in the relative proportions of actively and passively transported debris on the moraines rather than progressive modification of actively transported clasts these analyses also indicate that actively transported clasts form the dominant component of the moraines particularly near the former glacier terminus further applications of the approach developed here are suggested