crustal stress and seismic activity in the ionian archipelago as inferred by satellite and ground based observations kefallinia greece different observational techniques are compared in order to investigate possible correlations in seismic activity the study site is the island of kefallinia greece where measure ments available included 1 dinsar dgps and dem data 2 soil exhalation measured by monitoring radon rn well content and 3 acoustic emissions ae at high and low frequency point like records with high temporal resolution ae records provide 1 relative time variation of the applied stress intensity and 2 the state of fatigue of stressed rock volumes the ae source our results indicate that the large spatial scale poor time resolution may be considered quite sat isfactory whereas fractal analysis of the ae time series displayed some discrepancies when com pared to analogous investigations in the italian peninsula therefore some refinement is needed in order to reach more precise interpretations of the relevant information available with this kind of data however both sets of observations appear in agreement with each other although more exhaustive investigations would require a suitable array of point like ae and rn or other measuring sites as well as longer data series the latter are particulary helpful for detailed interpretations of the different occurrences within tectonically complex settings where crustal stress crises are marked by various types of geological phenomena

automated mapping of land components from digital elevation data an algorithm for automating the mapping of land components from digital elevation data is described land components are areas of relatively uniform slope and aspect and often correspond with ridge crests shoulders head slopes back slopes or foot slopes aspect regions which generally span from stream to ridge are first identified by generalizing an aspect map derived from digital elevation data the aspect regions are then split successively into land components by grouping pixels above or below an automatically determined contour of elevation or distance from stream the contour approximates a slope break the land components mapped in this way give a complete polygonization of a hilly landscape and are a reasonable approximation of manually mapped land components

petrology of futuna island lavas new hebrides an example of calc alkaline magmatism associated with the initial stages of back arc spreading abstract petrologic and chemical data are presented for samples from futuna island located behind the new hebrides island arc quartz normative basalts and basaltic andesites are the most abundant lava types there are mineralogically and chemically similar to the volcanic products of the central chain volcanic islands ambrym and aoba and other typical calc alkaline suites the lavas are enriched in the lil elements and depleted in ti and other transition elements their variations are consistent with fractionation of olivine fe ti oxide pyroxenes low ca and ca rich and plagioclase incompatible element ratios and abundances suggest that primary liquids were generated by complex mechanisms but a mantle source is needed to explain the data the most consistent problems are the concomitant and strong types of fractionation such as la ta and zr y whereas other coupled elements nb ta zr ta show chondritic ratios

application of self organizing map and srtm data to characterize yardangs in the lut desert iran abstract yardangs an exclusive landform due to intensive wind erosion cover a large area in the hyper arid lut desert of iran this paper presents a new approach using self organizing map som as unsupervised algorithm of artificial neural networks for analysis and characterization of yardangs nowadays the shuttle radar topography mission srtm with 3 arc sec data approximately 90 m resolution and nearly world wide coverage provides uniform good quality data the srtm 3 arc sec data were re projected to a 90 m utm grid bivariate quadratic surfaces with moving window size of 5 5 were fitted to this dem the first derivative slope steepness and the second derivatives minimum maximum curvature and cross sectional curvatures were calculated as geomorphometric parameters used as input to the soms 42 soms with different learning parameter settings e g initial and final radius number of iterations and the effect of random initial weights on average quantization error were investigated a som with a low average quantization error 0 1040 was used for further analysis feature space analysis morphometric signatures three dimensional inspection auxiliary data like landsat etm and high resolution satellite imagery from quickbird facilitated the assignment of semantic meaning to the output classes in terms of geomorphometric features results are provided in a geographic information system as thematic maps of landform entities based on form and slope e g yardangs ridge corridors valley or planar areas the results showed that all yardangs and corridors were clearly recognized and classified by this method when their width was larger than the dem resolution but became unrecognizable if their width is much smaller than the grid resolution the identified yardangs and corridors are aligned nnw sse parallel to the prevailing direction of the strong local 120 days wind and cover about 31 and 42 of the study area respectively the results demonstrate that som is a very efficient tool for analyzing aeolian landforms in hyper arid environments that provides very useful information for terrain feature analysis in remote regions

andesite and dacite genesis via contrasting processes the geology and geochemistry of el valle volcano panama the easternmost stratovolcano along the central american arc is el valle volcano panama several andesitic and dacitic lava flows which range in age 5 10 ma are termed the old group after a long period of quiescence approximately 3 4 ma volcanic activity resumed approximately 1 55 ma with the emplacement of dacitic domes and the deposition of dacitic pyroclastic flows 0 9 0 2 ma these are referred to as the young group all of the samples analyzed are calc alkaline andesites and dacites the mineralogy of the two groups is distinct two pyroxenes occur in the old group rocks but are commonly absent in the young group in contrast amphibole has been found only in the young group samples several disequilibrium features have been observed in the minerals e g oscillatory zoning within clinopyroxenes these disequilibrium textures appear to be more prevalent among the old as compared with the young group samples and are most likely the result of magma mixing assimilation and or polybaric crystallization mass balance fractionation models for major and trace elements were successful in relating samples from the old group but failed to show a relationship among the young group rocks or between the old and young group volcanics we believe that the old group volcanics were derived through differentiation processes from basaltic magmas generated within the mantlewedge the young group however does not appear to be related to more primitive magmas by differentiation the young group samples cannot be related by fractionation including realistic amounts of amphibole distinctive geochemical features of the young group including la yb ratios 15 yb 1 sr y 150 and y 6 suggest that these rocks were derived from the partial melting of the subducted lithosphere these characteristics can be explained by the partial melting of a source with residual garnet and amphibole dacitic material with the geochemical characteristics of subducted lithosphere melting is generated apparently only where relatively hot crust is subducted based on recent work the young dacite genesis at el valle volcano is related to the subduction of relatively hot lithosphere

the digital elevation model of italy for geomorphology and structural geology abstract the geomorphological setting and main geo structural features of the central southern italian peninsula have been investigated by creating and analyzing a digital elevation model dem and derived slope aspect and shaded relief images the dem has been assembled from the mean heights archive provided by the italian geological survey for the whole country the elevation data exhibit a grid mesh spacing of 7 5 latitude and 10 longitude firstly three different methods for calculating from a dem slope and aspect are discussed the four contiguous right triangles the maximum downward gradient and the bicubic spline first derivative the resulting maps have been compared with each other at regional scale and for a small area with a slope map obtained by using classical techniques the main goal of the comparison has been the choice of the best technique for the computation of the digital slope map of italy the four contiguous right triangles method yields better results both at local and at regional scale and is being used to create from the dem a slope map and a shaded relief of the whole country which will be published by the italian geological survey secondly the integrated analysis of dem derived slope digital map and shaded relief has permitted verification for the italian peninsula of the trends of already mapped fractures and faults and detection of previously unmapped structures showing morphological evidence the analysis of 1520 regional structural features has showed that the morphological setting of the studied area is strictly related to the tectonics about 90 of the mapped faults and folds are detectable on the shaded relief which proved to be the most useful byproduct of the dem for morphological analysis

an automated method to extract fluvial terraces from digital elevation models the vesdre valley a case study in eastern belgium abstract fluvial terraces are a powerful tool for unraveling the combined tectonic and climatic conditions that controlled directly or indirectly the quaternary incision of rivers terrace long profiles are usually retrieved from sparse traces of ancient floodplains preserved in the present topography however when these traces classically collected from topographic maps aerial photographs and field analyses are too few the inferred profiles may be questionable yet the now available high quality and high resolution digital elevation models dems offer an opportunity to increase greatly the quantity of information usable to reconstruct terrace profiles therefore the purpose of this study was to develop a new dem based method of terrace recognition in order to create a larger database and better constrain the profile reconstruction moreover particular procedures of image and numerical processing were defined to fully automate the analysis basically our method relies on the production of bivariate scatter plots depicting the relation between slope and relative altitude i e the altitude above the current alluvial plain for all pixels of successive sections of the valley for each scatter plot the curve of the lowest slope values observed at every relative altitude is smoothed and its minima are assumed to locate the altitudes of the terrace elements preserved in the section we successfully tested this method in the vesdre valley incised in the ne ardenne massif e belgium notably identifying fault deformation of the profiles the main advantages of our approach are its objectivity exhaustiveness and rapidity allowing fast and coherent analysis of many rivers over extended regions

geochemistry vs seismo tectonics along the volcanic new hebrides central chain southwest pacific abstract compositional variations major and trace element of pleistocene to present rocks along the volcanic new hebrides central chain southwest pacific are presented and discussed using a new set of analyses we focus in particular on the anomalous mg k lile and lree rich and al and si poor character of the basalts from aoba and santa maria volcanoes and to a lesser extent from ambrym volcano all located in the area where the d entrecasteaux zone collides with the arc in addition we note a compositional transition from normal arc basalts to boninite related high mg andesites at the southern termination of the nhcc the peculiar composition of the rocks of the volcanoes facing the d entrecasteaux zone has traditionally been related more or less directly to the collision subduction occurring in this area we present an alternative hypothesis of a strong geochemical anomaly under santa maria and aoba volcanoes unrelated to this collision in this model a westward and upward invasion of dupal type enriched mantle corroborated by the pattern of intermediate seismicity occurs under this part of the arc in strong contrast to the usual pacific type morb mantle source present under all other volcanoes of the nhcc such a dupal type source may explain the anomalous geochemistry of the resulting volcanic products

magmatology of mt pelee martinique f w i ii petrology of gabbroic and dioritic cumulates abstract the study of 24 plutonic xenoliths collected from mt pelee pyroclastic deposits shows that they can be subdivided into anorthite pargasite salite bearing gabbroic adcumulates type i olivine bearing type ii magnetite bearing and bytownite hornblende hypersthene augite bearing dioritic orthocumulates additionally olivine diopside pargasite and anorthite from a basaltic megacryst rich ash layer have been considered mineralogical data show continuous and progressive variations in the compositions of the solid phases with increase of fe fe mg ratios during the petrographic evolution of the investigated cumulate xenoliths thermobarometric data on minerals or mineral liquid pairs indicate a decrease of crystallization temperatures from about 1090 c in gabbroic assemblages to about 850 c in dioritic assemblages the gabbroic assemblage is believed to form in a water bearing environment from a derivative calc alkaline liquid at sufficient depth to stabilize al rich pargasite i e 8 9 kbar we suggest that the materials investigated may represent respectively the bottom megacrysts the walls type i and ii gabbroic adcumulates and the roof dioritic orthocumulates of stratified magma chamber s underlying mt pelee volcano

an automated method for producing synoptic regional maps of river gradient variation procedure accuracy tests and comparison with other knickpoint mapping methods abstract the study of abrupt changes in longitudinal river profiles or knickpoints is currently approached through an empirical power law the slope area relationship results based on digital elevation model dem analyses and stream extractions are generally intended to determine crustal uplift rates and identify transient landscape conditions in this article we present an alternative geomorphometric method for locating knickpoints and knickzones based on local slope gradient and curvature attributes intended as a rapid regional scale automated knickpoint detection technique the accuracy of this slope curvature method is tested on two digital elevation grids nasa s srtm ground resolution of 90 m resampled here to 75 m and the aster dem 15 m in the sierra nacimiento new mexico usa a basement cored mountain range recently exhumed by waves of headward drainage integration in response to remote tectonic deformation in the adjacent rio grande rift out of every 10 gradient anomalies detected by the srtm derived numeric routine up to 8 are certifiable knickpoints recognized among a population of georeferenced occurrences surveyed in the field an independent comparison with the slope area method provided a further accuracy test which was particularly useful at sites that could not be validated in the field for practical reasons given the low tectonic activity of the study area the majority of knickpoints was also found to coincide with lithologic boundaries making it difficult without further geomorphological data to single out dynamic knickpoints directly caused by the upstream propagation of channel instabilities relating to base level change

computer assisted discrimination of morphological units on north central crete greece by applying multivariate statistics to local relief gradients traditional manual methods have been employed for decades to measure geomorphometric properties from topographic maps such measurement techniques tend to be tedious and time consuming and the designated landform elements cannot be easily overlaid on any digital map and imagery for further applied research this study deals with a new quantitative geomorphometric procedure based on the multivariate statistical analysis of local topographic gradients within a part of northcentral crete this method employs sets of computer algorithms that automatically extract and classify geomorphometric properties from digital elevation models dems this was done by evaluating the morphological setting around each pixel of the dem along the eight azimuth directions isodata unsupervised classification was implemented to generate 10 morphometric classes showing the spatial distribution of areas with a similar geomorphic scenario results revealed that this approach permitted a quick estimation of the spatial distribution of morphologically homogeneous terrain units it also demonstrated the ability of the delineated landform elements to be superimposed on any digital map and imagery for further investigation this became apparent during the examination of the relationship between the geomorphological units and the land cover land use types in the study area both relative association and the dominant land cover land use types in relation to geomorphological units are presented d 2003 elsevier b v all rights reserved

mineralogy of erromango lavas new hebrides evidence of an early stage of fractionation in island arc basalts abstract the orogenic volcanic rocks of erromango island are divided into a quaternary theoleiitic group and an older pliocene one showing calc alkalic affinity the microprobe mineralogy of these lavas agrees with this geochemical distinction and indicates a marked iron enrichment trend in the recent tholeiitic lavas whereas titanomagnetite occurs as early formed phenocrysts al cr mg rich only in pliocene basalts some ni and mg rich olivine phenocrysts fo88 and unusual chemically zoned clinopyroxene megacrysts are described from pliocene basic lavas and interpreted as deep fractionated minerals the large compositional range of these latter diopside core to augite rim through salite intermediate zone leads us to discuss the physical conditions and the corresponding cation substitutions prevailing during their formation diopside cores crystallized at depths of about 20 km from a relatively primitive melt the formation of salite is considered to be the result of concomitant fractionation of mg rich phases and increase of f o 2 an early stage of fractionation of cr bearing diopside ni bearing olivine would account for the typical cr and ni depletion of erromango lavas

petrology of matthew and hunter volcanoes south new hebrides island arc southwest pacific abstract matthew and hunter the two southernmost active volcanoes of the new hebrides island arc southwest pacific differ markedly from the other mainly tholeiitic quaternary volcanoes of this arc geodynamically related to the new hebrides subduction zone they also lie close to the southern limb of the active expanding ridge of the north fiji basin both volcanoes are made up of acid medium k calcalkaline orogenic andesites containing a variety of inclusions pyroxene and gabbroic cumulates as well as doleritic cognate inclusions this paper presents the first systematic petrographic and chemical study of these volcanics and their inclusions trace element geochemistry and rare earth element modelling suggest that the two volcanoes developed from successive batches of similar parental magmas originating from limited partial fusion of garnet peridotite in the mantle wedge various degrees of fractional crystallization of these batches led to the formation of three volcanic suites hunter little fractionated west matthew moderately fractionated and east matthew highly fractionated moreover on matthew island no correlation exists between the degree of fractionation and the eruptive chronology the youngest edifice west matthew being less evolved than the older one east matthew

automatically derived catchment boundaries and channel networks and their hydrological applications abstract a method of generating drainage networks and catchment boundaries from gridded ground elevation data a digital terrain model is presented the method includes an algorithm for coping with localised low points in the data the paper suggests two objective ways of comparing the conventionally mapped with the automatically generated drainage network emphasis is placed on the way that this approach is capable of benefiting a variety of hydrological applications in particular the automatic estimation of flow statistics from catchment characteristics

geomorphometric analysis for characterizing landforms in morelos state mexico landforms can be described and quantified into simple relief elements by parametrization of digital elevation model dem in this research we investigate the use of morphometric parameters and a new classification scheme to characterize selected elemental forms associated with landforms we apply and test this methodology on a geomorphologically diverse region located in central mexico these simple elements are known as morphometric classes and include ridge plane channel pit peak and pass these classes correspond to real entities and are of practical significance the morphometric classes were grouped according to their areal parameters ridge plane and channel and pointed parameters pit peak and pass which can be used to form the basis of a system of characterization and classification of landforms landform elements display statistically significant compositional differences with respect to their proportions of morphometric classes this in turn can be plotted onto a diagram of characterization and classification known as a double ternary diagram dtd which comprises both areal and pointed parameters and any combination thereof the dtd is useful for studying geomorphological processes wherein areal and point values and properties have expressions which are topographically quantifiable

petrology geochemistry and tectonic implications of volcanics dredged from the intersection of the yap and mariana trenches abstract rocks dredged from the forearc very close to the intersection of the yap and mariana trenches include a suite of highly depleted arc tholeiites and several samples of transitional to slightly alkaline basalt the tholeiites range from magnesian quartz tholeiites with 0 46 0 6 tio2 to andesites with up to 62 sio2 and 8 2 feo all show pronounced lree depletion and have very low contents of ba and sr they are postulated to have been produced by partial melting of upper mantle peridotite residual after morb extraction following influx of hydrous fluids from the subducted slab while these fluids were responsible for small enrichments in ba k rb and sr in melts generated lree were not involved in the metasomatism and the strong lree depletion probably reflects the unmodified depleted source peridotite the second lava suite includes slightly ne normative ti augite bearing basalts with convex upward ree patterns showing slight lree depletion la sm n 0 76 the chemical features of these basalts support affinities with basalts erupted during the earliest stages of backarc basin opening a k ar age on one sample 7 8 1 3m y is in good agreement with the initial opening of the mariana trough the tectonic significance of the dredged arc tholeiite suite is less obvious a k ar age of10 8 0 4 my on one andesite and the occurrence of similar lavas in dredges from at least 300 km along the length of the yap arc suggest that subduction was occurring beneath the yap arc in the late miocene after overthrusting of the yap greenschist allochthon and while calc alkaline arc magmatism was occurring further north on the west mariana ridge we suggest that the depleted arc tholeiites in dredge 1438 were generated by abnormally shallow melting of upper mantle beneath the yap forearc following subduction beneath this area of young hot sorol trough crust these arc tholeiites represent a magma type transitional between more typical arc tholeiites e g tongan and high mg andesites and boninites

expert driven semi automated geomorphological mapping for a mountainous area using a laser dtm in this paper a semi automated method is presented to recognize and spatially delineate geomorphological units in mountainous forested ecosystems using statistical information extracted from a 1 m resolution laser digital elevation dataset the method was applied to a mountainous area in austria first slope angle and elevation characteristics were determined for each key geomorphological unit occurring in the study area second a map of slope classes derived from the laser dtm was used in an expert driven multilevel object oriented approach the resulting classes represent units corresponding to landforms and processes commonly recognized in mountain areas fluvial terrace alluvial fan slope with mass movement talus slope rock cliff glacial landform shallow incised channel and deep incised channel the classification result was compared with a validation dataset of geomorphological units derived from an analogue geomorphological map for the above mentioned classes the percentages of correctly classified grid cells are 69 79 50 64 32 61 23 and 70 respectively the lower values of 32 and 23 are mainly related to inaccurate mapping of rock cliffs and shallow incised channels in the analogue geomorphological map the accuracy increased to 76 and 54 respectively if a buffer is applied to these specific units it is concluded that high resolution topographical data derived from laser dtms are useful for the extraction of geomorphological units in mountain areas

digital modelling of landscape and soil in a mountainous region a neuro fuzzy approach abstract research on genetic relationships between soil and landforms has largely improved soil mapping recent technological advances have created innovative methods for modelling the spatial soil variation from digital elevation models dems and remote sensors this generates new opportunities for the application of geomorphology to soil mapping this study applied a method based on artificial neural networks and fuzzy clustering to recognize digital classes of land surfaces in a mountainous area in north central venezuela the spatial variation of the fuzzy memberships exposed the areas where each class predominates while the class centres helped to recognize the topographic attributes and vegetation cover of each class the obtained classes of terrain revealed the structure of the land surface which showed regional differences in climate vegetation and topography and landscape stability the land surface classes were subdivided on the basis of the geological substratum to produce landscape classes that additionally considered the influence of soil parent material these classes were used as a framework for soil sampling a redundancy analysis confirmed that changes of landscape classes explained the variation in soil properties p 0 01 and a kruskal wallis test showed significant differences p 0 01 in clay hydraulic conductivity soil organic carbon base saturation and exchangeable ca and mg between classes thus the produced landscape classes correspond to three dimensional bodies that differ in soil conditions some changes of land surface classes coincide with abrupt boundaries in the landscape such as ridges and thalwegs however as the model is continuous it disclosed the remaining variation between those boundaries

geomorphometric feature analysis using morphometric parameterization and artificial neural networks this paper presents a semi automatic method using an unsupervised neural network to analyze geomorphometric features as landform elements the shuttle radar topography mission srtm provided detai

an automated approach to the classification of the slope units using digital data abstract digital elevation and remote sensing data sets contain different yet complementary information related to geomorphological features digital elevation models dems represent the topography or land form whereas remote sensing data record the reflectance emittance or spectral characteristics of surfaces computer analysis of integrated digital data sets can be exploited for geomorphological classification using automated methods developed in the remote sensing community in the present study geomorphological classification in a moderate to high relief area dominated by slope processes in southwest yukon territory canada is performed with a combined set of geomorphometric and spectral variables in a linear discriminant analysis an automated method was developed to find the boundaries of geomorphological objects and to extract the objects as groups of aggregated pixels the geomorphological objects selected are slope units with the boundaries being breaks of slope on two dimensional downslope profiles each slope unit is described by variables summarizing the shape topographic and spectral characteristics of the aggregated group of pixels overall discrimination accuracy of 90 is achieved for the aggregated slope units in ten classes

the respiratory health hazards of volcanic ash a review for volcanic risk mitigation studies of the respiratory health effects of different types of volcanic ash have been undertaken only in the last 40 years and mostly since the eruption of mt st helens in 1980 this review of all published clinical epidemiological and toxicological studies and other work known to the authors up to and including 2005 highlights the sparseness of studies on acute health effects after eruptions and the complexity of evaluating the long term health risk silicosis non specific pneumoconiosis and chronic obstructive pulmonary disease in populations from prolonged exposure to ash due to persistent eruptive activity the acute and chronic health effects of volcanic ash depend upon particle size particularly the proportion of respirable sized material mineralogical composition including the crystalline silica content and the physico chemical properties of the surfaces of the ash particles all of which vary between volcanoes and even eruptions of the same volcano but adequate information on these key characteristics is not reported for most eruptions the incidence of acute respiratory symptoms e g asthma bronchitis varies greatly after ashfalls from very few if any reported cases to population outbreaks of asthma the studies are inadequate for excluding increases in acute respiratory mortality after eruptions individuals with pre existing lung disease including asthma can be at increased risk of their symptoms being exacerbated after falls of fine ash a comprehensive risk assessment including toxicological studies to determine the long term risk of silicosis from chronic exposure to volcanic ash has been undertaken only in the eruptions of mt st helens 1980 usa and soufriere hills montserrat 1995 onwards in the soufriere hills eruption a long term silicosis hazard has been identified and sufficient exposure and toxicological information obtained to make a probabilistic risk assessment for the development of silicosis in outdoor workers and the general population a more systematic approach to multi disciplinary studies in future eruptions is recommended including establishing an archive of ash samples and a website containing health advice for the public together with scientific and medical study guidelines for volcanologists and health care workers

assessing the impact of soil surface characteristics on vineyard erosion from very high spatial resolution aerial images cote de beaune france we describe a new method to map intra plot soil surface heterogeneities at a 5 cm spatial resolution our approach unites aerial image classification acquired at very high spatial resolution vhsr with local soil sampling vhsr aerial image processing based on image classification allows precise mapping of the spatial distribution of soil surfaces soil sampling defines soil typology by physical and chemical characteristics this method has been applied to a plot area located on the hillslopes of burgundy vineyards monthelie france where decennial erosion data were already available in order to assess the effect of soil surface characteristics and slope angle on erosion intensity and localisation from this method four classes of radiance were distinguished and interpreted as four soil surface state classes ssc defining specific areas within the studied plot these sscs have been characterised by their grain size distribution their organic carbon calcium carbonate and total nitrogen contents by allowing soil surface states to be mapped at five centimetre resolution this approach provides novel insights into the characterisation of soil patterns and into erosion analysis on cultivated hillslopes our work shows that the spatial distribution of soil erosion is related to the local slope steepness but also to the spatial distribution of stoniness that results from water and tillage erosion processes

geomorphons a pattern recognition approach to classification and mapping of landforms abstract we introduce a novel method for classification and mapping of landform elements from a dem based on the principle of pattern recognition rather than differential geometry at the core of the method is the concept of geomorphon geomorphologic phonotypes a simple ternary pattern that serves as an archetype of a particular terrain morphology a finite number of 498 geomorphons constitute a comprehensive and exhaustive set of all possible morphological terrain types including standard elements of landscape as well as unfamiliar forms rarely found in natural terrestrial surfaces a single scan of a dem assigns an appropriate geomorphon to every cell in the raster using a procedure that self adapts to identify the most suitable spatial scale at each location as a result the method classifies landform elements at a range of different spatial scales with unprecedented computational efficiency a general purpose geomorphometric map an interpreted map of topography is obtained by generalizing allgeomorphons to a small number of the most common landform elements due to the robustness and high computational efficiency of the method high resolution geomorphometric maps having continental and even global extents can be generated from giga cell dems such maps are a valuable new resource for both manual and automated geomorphometric analyses in order to demonstrate a practical application of this new method a 30 m cell 1 geomorphometric map of the entire country of poland is generated and the features and potential usage of this map are briefly discussed the computer implementation of the method is outlined the code is available in the public domain

elementary forms for land surface segmentation the theoretical basis of terrain analysis and geomorphological mapping abstract land surface morphology is fundamental to geomorphological mapping and many gis applications review and comparison of various approaches to segmentation of the land surface reveals common features and permits development of a broad theoretical basis for segmentation and for characterization of segments and their boundaries within the context of defining landform units that maximise internal homogeneity and external differences this paper introduces the concept of elementary forms segments units defined by constant values of fundamental morphometric properties and limited by discontinuities of the properties the basic system of form defining properties represents altitude and its derivatives constant values of which provide elementary forms with various types of homogeneity every geometric type of elementary form can be characterized by a defining function which is a specific case of the general polynomial fitted function various types of boundary discontinuity and their connections and transformations into other types of morphological unit boundaries are analysed the wealth of types of elementary forms and their boundaries is potentially unbounded and thus is sufficient to cover the real variety of landforms elementary forms in the basic set proposed here have clear potential for genetic and dynamic interpretation a brief worked example documents the possibility of analytical computation of various models of ideal elementary forms for particular segments of landform ideal elementary forms can be considered as attractors to which the affinity of surface segments can be measured by multivariate statistical methods the use of the concept of elementary forms in landscape segmentation is promising and it could be adapted for elementary segmentation of various other spatial fields

discrimination of fluvial eolian and neotectonic features in a low hilly landscape a dem based morphotectonic analysis in the central pannonian basin hungary abstract the godoll hills a low relief terrain within the central pannonian basin in hungary is characterised by moderate tectonic deformation rates although typical tectonic landforms are not clearly recognisable in the study area this paper succeeded in discriminating between tectonically controlled landforms and features shaped by fluvial erosion or deflation with no tectonic control dem based morphometric parameters including elevation slope and surface roughness enabled the delineation of two nw se trending spearhead shaped ridges separated by a wide rectilinear valley of the same strike although directional statistics suggested possible tectonic control of nw se striking landforms precise morphometry completed with an analysis of subsurface structures rejected their tectonic preformation deflation plays a significant role in shaping the area and the presence of two large scale yardangs separated by a wind channel is proposed in temperate continental areas of europe no deflational landforms of such scale have been described so far suggesting that pleistocene wind power in periglacial areas was more significant than it was previously thought characteristic drainage patterns and longitudinal valley profiles enabled the recognition of areas probably affected by neotectonic deformation a good agreement was observed between locations of quaternary warping predicted by the morphometric study and subsurface structures revealed by the tectonic analysis zones of surface uplift and subsidence corresponded to anticlinal and synclinal hinges of fault related folds in low relief and slowly deforming areas where exogenous forces may override tectonic deformation only the integrated application of morphometric and subsurface structural indications could assure correct interpretation of the origin of various landforms while a morphometric study alone could have led to misinterpretation of some morphometric indices apparently suggesting tectonic preformation on the other hand the described morphological expression of subsurface structures could verify quaternary age of the deformation