Rethinking Wat’s Dyke: A Monument’s Flow in a Hydraulic Frontier Zone

Britain’s second-longest early medieval monument – Wat’s Dyke – was a component of an early medieval hydraulic frontier zone rather than primarily serving as a symbol of power, a fixed territorial border or a military stop-line. Wat’s Dyke was not only created to monitor and control mobility over land, but specifically did so through its careful and strategic placement by linking, blocking and overlooking a range of watercourses and wetlands. By creating simplified comparative topographical maps of the key fluvial intersections and interactions of Wat’s Dyke for the first time, this article shows how the monument should not be understood as a discrete human-made entity, but as part of a landscape of flow over land and water, manipulating and managing anthropogenic and natural elements. Understanding Wat’s Dyke as part of a hydraulic frontier zone not only enhances appreciation of its integrated military, territorial, socio-economic and ideological functionality and significance, most likely the construction of the middle Anglo-Saxon kingdom of Mercia, it also theorises Wat’s Dyke as built to constitute and maintain control both across and along its line, and operating on multiple scales. Wat’s Dyke was built to manage localised, middle-range as well as long-distance mobilities via land and water through western Britain and beyond.

Automatic vectorization of point symbols on archive maps using deep convolutional neural network

Archive topographical maps are a key source of geographical information from past ages, which can be valuable for several science fields. Since manual digitization is usually slow and takes much human resource, automatic methods are preferred, such as deep learning algorithms. Although automatic vectorization is a common problem, there have been few approaches regarding point symbols. In this paper, a point symbol vectorization method is proposed, which was tested on Third Military Survey map sheets using a Mask Regional Convolutional Neural Network (MRCNN). The MRCNN implementation uses the ResNet101 network improved with the Feature Pyramid Network architecture and is developed in a Google Colab environment. The pretrained network was trained on four point symbol categories simultaneously. Results show 90% accuracy, while 94% of symbols detected for some categories on the complete test sheet.

Identification And Characterization Of Geoheritage Resources At Hulu Langat, Selangor

Identification and characterization of geodiversity for sites need more systematic approach for the purpose of conserving site with high geoheritage value. The present of igneous and metamorphic rock at Hulu Langat creates diversity in rock, features and geomorphological features includes hot spring, waterfall, hill and mountain that hold potential as a protected geosite of heritage value. Besides, the previous tin mining activities created by the contact metamorphism, left series of lakes and ponds while the nearby mountain is susceptible area as watershed that turn into dams around the area. Analysis on topographical maps, satellite image and aerial photograph interpretation aided in identification potential geosite based on geomorphological diversity. A total of 31 potential geosites with geological-scientific value have been identified in this study compare to 10 from the previous study. The potential geosite have been classified into rock diversity, natural landscape diversity and anthropogenic landscape diversity. Characterisation recognise 6 of these potential geosite are best example or tip location to illustrate the geological element, 4 of these geosites are the only occurrence of the geological element, 27 of the potential geosites are well preserved and 4 hold the scientific knowledge written in the international journal. The identification and characterisation of geoheritage resources are crucial steps before evaluation or assessment, ranking and conservation or development being propose, while strengthen the conservation geology approach.

The Retreat of Mountain Glaciers since the Little Ice Age: A Spatially Explicit Database

Most of the world’s mountain glaciers have been retreating for more than a century in response to climate change. Glacier retreat is evident on all continents, and the rate of retreat has accelerated during recent decades. Accurate, spatially explicit information on the position of glacier margins over time is useful for analyzing patterns of glacier retreat and measuring reductions in glacier surface area. This information is also essential for evaluating how mountain ecosystems are evolving due to climate warming and the attendant glacier retreat. Here, we present a non-comprehensive spatially explicit dataset showing multiple positions of glacier fronts since the Little Ice Age (LIA) maxima, including many data from the pre-satellite era. The dataset is based on multiple historical archival records including topographical maps; repeated photographs, paintings, and aerial or satellite images with a supplement of geochronology; and own field data. We provide ESRI shapefiles showing 728 past positions of 94 glacier fronts from all continents, except Antarctica, covering the period between the Little Ice Age maxima and the present. On average, the time series span the past 190 years. From 2 to 46 past positions per glacier are depicted (on average: 7.8).

Determination of the Northwestern Extensions of the Bai Hassan Field (Daoud Culmination) and Its Geological Relationship with Ismail -1 Area, Northern Iraq

The Ismail-1 is located northwest of the Bai Hassan Field (Daoud Culmination), within the administrative boundaries of the provinces of Kirkuk and Erbil, which was later named Ismail Field. The objective of the research is to determine the geological relationship (structural and reservoir) of the well Ismail-1 with the Bai Hassan Field (Daoud Culmination). Based on geological and reservoir studies and seismic surveys of the region, the first basis of the research was based on the stratigraphy, structural, reservoir and morph structure aspects of this relationship.In the beginning, the serial sequence of the well was reviewed and compared with David's wells. Then, cross-sections and long sections were drawn through the wells of Ismail-1 and Daoud wells, as well as, the fluid levels dotted on such sections. After that, a structural contour map was drawn on top of Jeribe Formation for the area of well Ismail-1 which is currently known as Ismail Field and part of the Bai Hassan Field (Daoud Culmination), depending on the structural and reservoir data. It was found that the area of the well Ismail-1 is an asymmetrical convex fold, the southwestern flank is more inclined than the northeastern flank, and the Daoud Culmination and the Ismailfold is separated by a narrow saddle. However, depending on the structural contour map of the top of Jeribe Formation (-1325) meters from the mean sea level, the deeper levels of which surround the two Culminations together, the similarity of the reservoir properties and the different levels of fluid in the Daoud Culmination and the area of the Ismail-1, all confirm that they are two separate Culminations of one field. So the so-called Ismail Field can be considered a third Culmination called Ismail Culmination of the Bai Hassan Field.Using topographical maps and satellites data, the morph structure and geomorphological phenomena of the northwestern extensions of the Bai Hassan Field (the area of well Ismail-1) and towards the Quir Field, were studied and the northwestern aerial extensions of about 18 km length and 5 km width were delineated.Thus, the Bai Hassan Field is consisting of three Culminations (from the southeast to the northwest, Kithka, Daoud and Ismail Culminations) with a total length about 50 km.

Topographic numerosity maps cover subitizing and estimation ranges

Numerosity, the set size of a group of items, helps guide behaviour and decisions. Non-symbolic numerosities are represented by the approximate number system. However, distinct behavioural performance suggests that small numerosities, i.e. subitizing range, are implemented differently in the brain than larger numerosities. Prior work has shown that neural populations selectively responding (i.e. hemodynamic responses) to small numerosities are organized into a network of topographical maps. Here, we investigate how neural populations respond to large numerosities, well into the ANS. Using 7 T fMRI and biologically-inspired analyses, we found a network of neural populations tuned to both small and large numerosities organized within the same topographic maps. These results demonstrate a continuum of numerosity preferences that progressively cover both the subitizing range and beyond within the same numerosity map, suggesting a single neural mechanism. We hypothesize that differences in map properties, such as cortical magnification and tuning width, underlie known differences in behaviour.

Little Ice Age advance of Kvískerjajöklar, Öræfajökull, Iceland. A contribution to the assessment of glacier variations in Iceland since the late 18th century

We describe the changes of the Kvískerjajöklar outlet glaciers in SE Iceland (presently ranging 600–1600 m a.s.l.), from their Little Ice Age maximum (LIAmax) to the present. We assume that glacier extent of the late 19th century approximately describes LIAmax although the glaciers already reached their peak extent in the 18th century. The former glacier margins were delineated from moraines, historical descriptions, topographical maps, aerial and oblique photographs, Landsat images and a lidar DEM. Along the previous glacier margins, elevation differences with respect to the lidar DEM of 2011 were estimated and contour maps of the glacier drawn at selected dates, maintaining the shape of the glacier surface as available maps. During the period 1890 to 2011, the outlets lost -0.4 m a-1 water equivalent evenly distributed over their surface and their area was reduced by 37% (from 10 km2 to 6.4 km2, 0.03 km2 a-1, 0.43 km3 water equivalent in total, i.e. 0.003 km3 w.e. a-1).

Human gaze is precisely aligned with the foveolar cone topography of both eyes

The small physical depression of the human retina, termed fovea, is the functional center of human vision, providing an acute sense of visual space and color, but it is yet unclear if the exact arrangement of the few thousand photoreceptors at the foveal center is relevant for visual behavior. By employing adaptive optics in vivo imaging and micro-stimulation, we created complete topographical maps of the foveolar cone mosaics in both eyes of 20 healthy participants while simultaneously recording the exact retinal location of a fixated visual object in a psychophysical experiment. We found that the locus of fixation was systematically shifted away from the topographical centers towards a naso-superior quadrant of the foveolea in both eyes, thereby creating an enlarged binocular area of visual space sampled by high density cones. This demonstrates a finely tuned link between the development of the cellular arrangement of the photoreceptors of the foveola and visual behavior.