Modelling the spatial distribution of DEM Error

Assessment of a DEM’s quality is usually undertaken by deriving a measure of DEM accuracy – how close the DEM’s elevation values are to the true elevation. Measures such as Root Mean Squared Error and standard deviation of the error are frequently used. These measures summarise elevation errors in a DEM as a single value. A more detailed description of DEM accuracy would allow better understanding of DEM quality and the consequent uncertainty associated with using DEMs in analytical applications. The research presented addresses the limitations of using a single root mean squared error (RMSE) value to represent the uncertainty associated with a DEM by developing a new technique for creating a spatially distributed model of DEM quality – an accuracy surface. The technique is based on the hypothesis that the distribution and scale of elevation error within a DEM are at least partly related to morphometric characteristics of the terrain. The technique involves generating a set of terrain parameters to characterise terrain morphometry and developing regression models to define the relationship between DEM error and morphometric character. The regression models form the basis for creating standard deviation surfaces to represent DEM accuracy. The hypothesis is shown to be true and reliable accuracy surfaces are successfully created. These accuracy surfaces provide more detailed information about DEM accuracy than a single global estimate of RMSE

A Spreadsheet Program (ScallopEx) to Calculate Paleovelocities From Cave Wall Scallops

The determination of paleovelocities through analysis of scallops on cave walls is an important part of paleohydrologic analysis. The linked equations that must be solved to do this are cumbersome, though. This paper presents a spreadsheet program that simplifies the process. The user enters scallop lengths, paleotemperatures, and passage dimensions; and the program returns velocities

Clastic Sediments in the Butler Cave – Sinking Creek System, Virginia, USA

The Butler Cave - Sinking Creek System in Bath County, Virginia, consists of a master trunk passage along the axis of a syncline with a trellis arrangement of dip-oriented side caves. The western set of dip passages contain a sequence of massively and chaotically bedded sand and cobble sediments. Massive cobble fills also occur in the strike-oriented trunk passage. Cave passages on the eastern side of the syncline contain mostly sand and silt. The light fraction of the sediments consists predominantly of quartz and rock fragments. The sediments contain several percent heavy minerals composed of iron oxides, zircon, rutile, tourmaline and other minerals. Measurement of the visible and near infrared diffuse reflectance spectra shows at least three populations of sediments to be present: an iron-rich, clay-poor group; a clay-rich group; and a gypsiferous sediment. The iron minerals provided a paleomagnetic signal. Sediments from the trunk passage, deposited by recent underground drainage, contained a normal pole direction. Sediments from the dip passages were paleomagnetically reversed, showing the deposition dates from prior to 780,000 years. In one instance reversed polarity deposits overlie normal polarity, implying a minimum age of 990,000 years for the reversed sediments.   

How did Veternica Cave form?

Osim speleološke i turističke atraktivnosti, špilja Veternica čuva bogatstvo informacija o okolišnim uvjetima koji su vladali u geološkoj prošlosti. Sedimentne naslage ove špilje bile su predmet brojnih istraživanja, koja su posebno ojačala od sredine 20. stoljeća. U ovom radu dajemo sažeti povijesni prikaz geoloških istraživanja i detaljnije predstavljamo rezultate novih istraživanja provedenih u posljednjih dvadesetak godina. Kombiniranjem speleomorfološkog kartiranja, paleomagnetskih analiza potočnih (klastičnih) sedimenata te analiza određivanja starosti siga uran-torij (U-Th) metodom prvi su put dobiveni kronološki podaci o razvoju špilje Veternice tijekom posljednjih više od 600 000 godina geološke prošlosti. Izdvojeno je nekoliko speleogenetskih faza, koje su odraz izmjena dugih stabilnih i kraćih tektonski aktivnih razdoblja šireg područja. Tijekom razdoblja aktivnog tektonskog izdizanja Medvednice i posljedičnog spuštanja razine erozijske baze morfologija kanala brzo se prilagođavala brzini opadanja razine podzemne vode od oko 6 m u 10 000 godina. Pad razine vode usporediv je sa stopama izmjerenima u drugim špiljama smještenima u sličnim tektonski aktivnim područjima.Besides being a speleological and tourist attraction, Veternica Cave holds a wealth of information about environmental conditions of the geological past. Sedimentary deposits from this cave have been the subject of numerous investigations, especially since the middle of the 20th century. This article gives a concise historical account of geological research and presents new details about the results of research conducted in the last twenty years. By combining speleomorphological mapping, paleomagnetic analyses of stream (clastic) sediments, and dating of speleothems using the Uranium-Thorium (U-Th) method, it was possible for the first time to obtain chronological data on the development of Veternica Cave during the last over 600,000 years. The research identified several speleogenic phases that reflect alternating intervals of long and stable versus shorter and tectonically active periods within the wider area. During the active tectonic uplift of Medvednica Mountain. and the corresponding lowering of the erosional base level, the cave passage morphology quickly adapted to the decrease of ground water level, which occurred at the rate of about 6 m per 10,000 years. This rate is comparable to rates measured in other caves from similar tectonically active areas

Transgenerationales Trauma im Familiensystem

Das Ziel der vorliegenden Bachelorarbeit ist es, einen Überblick über transgenerationale Weitergabe von Traumata in Familien zu gewinnen und sich durch eine kunsttherapeutische Methode diesem schwierigen Thema in der Praxis anzunähern. Der Fokus liegt auf der systemischen Familientherapie sowie den unterschiedlichen Übertragungswegen und wiederkehrenden Themen innerhalb der Familie. Der praktische Bezug zur Kunsttherapie wird durch den projektiven Test Familie in Tieren von Brem-Gräser hergestellt. Mithilfe von Fallbeispielen einer selbst durchgeführten Studie konnte ein Verständnis für die Anwendung dieser Methode in der Kunsttherapie erlangt werden. Eine kritische Auseinandersetzung mit dem Test führt zu seiner Abwandlung bzw. Anpassung für den kunsttherapeutischen Alltag

CLASTIC SEDIMENTS IN CAVES – IMPERFECT RECORDERS OF PROCESSES IN KARST

Clastic sediments have played an important role in deciphering geologic history and processes since the inception of the discipline. Early studies of caves applied stratigraphic principles to karst deposits. The majority of cave deposits are breakdown and alluvium. The alluvial materials have been successfully investigated to determine ages of caves, landscape evolution, paleoenvironmental conditions, and paleobiota. Rapid stage changes and the possibility of pipe-full flow make cave deposits different than surface deposits. This and other factors present difficulties with interpreting the cave record, but extended preservation is afforded by the “roofing” of deposits. Dating by magnetism or isotopes has been successful in many locations. Caves can be expected to persist for 10 Ma in a single erosive cycle; most cave sediments should be no older than this