Activities to Develop a Spatial Perspective Among Students in Introductory Geography Courses

Abstract

Teaching students to gain a spatial perspective is one of the most difficult yet important components of geographic education. This paper presents a series of activities designed to develop a more comprehensive understanding of spatial concepts among students in introductory geography courses. The activities and content are most appropriate for high school or university undergraduate students. An evaluation of these activities demonstrates that they enhance the student's spatial perspective and their understanding of the role of spatial concepts in geography.     

Seismically induced landslide displacements: a predictive model

Newmark's model for predicting earthquake-induced landslide displacements provides a simple way to predict the coseismic displacements affecting a sliding mass subject to earthquake loading. In this model, seismic slope stability is measured in terms of critical acceleration, which depends on the mechanical soil properties, pore-pressure distribution, and slope geometry. The triggering seismic forces are investigated in terms of energy radiation from the source, propagation, and site effects, based on 190 accelerometric recordings from 17 Italian earthquakes with magnitudes between 4.5 and 6.8. The method is based on the calibration of relations having the general form of an attenuation law that relates the energy of the seismic forces to the dynamic shear resistances of the sliding mass to propagate the expected landslide displacements as an inverse function of the distance from the fault rupture; the amount of displacement computed through these relations provides a criterion to predict the occurrence of slope failures. Finally, maps showing, in a deterministic and a probabilistic way, the potential of seismically induced landslide displacements are displayed as a tool to provide seismic landslide scenarios and earthquake-induced landslide hazard maps, respectively.     

Thematic Map Analysis Using Multiple Regression

Thematic maps can be analyzed by multiple regression for (1) forward prediction where a younger geological structural map is written as a least-squares function of older maps for information on historical perspectives or (2) by backward prediction where an older map is regressed stepwise on a series of younger ones to aid in prospecting. The technique was evaluated by a series of structure maps on different geological horizons from the U.S. Midcontinent (Kansas) where the forward prediction proved more effective than backward. In forward prediction, the first map entered into a multiple regression is invariably the immediately underlying one as expected. On the other hand, the first map in a backward prediction is not necessarily related to stratigraphy which limits the utility of the technique for prospecting.     

Use of Noise to Augment Training Data: A Neural Network Method of Mineral–Potential Mapping in Regions of Limited Known Deposit Examples

One of the main factors that affects the performance of MLP neural networks trained using the backpropagation algorithm in mineral-potential mapping isthe paucity of deposit relative to barren training patterns. To overcome this problem, random noise is added to the original training patterns in order to create additional synthetic deposit training data. Experiments on the effect of the number of deposits available for training in the Kalgoorlie Terrane orogenic gold province show that both the classification performance of a trained network and the quality of the resultant prospectivity map increasesignificantly with increased numbers of deposit patterns. Experiments are conducted to determine the optimum amount of noise using both uniform and normally distributed random noise. Through the addition of noise to the original deposit training data, the number of deposit training patterns is increased from approximately 50 to 1000. The percentage of correct classifications significantly improves for the independent test set as well as for deposit patterns in the test set. For example, using ±40% uniform random noise, the test-set classification performance increases from 67.9% and 68.0% to 72.8% and 77.1% (for test-set overall and test-set deposit patterns, respectively). Indices for the quality of the resultant prospectivity map, (i.e. D/A, D × (D/A), where D is the percentage of deposits and A is the percentage of the total area for the highest prospectivity map-class, and area under an ROC curve) also increase from 8.2, 105, 0.79 to 17.9, 226, 0.87, respectively. Increasing the size of the training-stop data set results in a further increase in classification performance to 73.5%, 77.4%, 14.7, 296, 0.87 for test-set overall and test-set deposit patterns, D/A, D × (D/A), and area under the ROC curve, respectively.     

Upper Cretaceous marine‐continental transition (Leonese Area,NW Spain) defined from integrated outcrop and seismic stratigraphy

The Upper Cretaceous succession of the Leonese Area (NW Spain) comprises mixed clastic and carbonate sediments. This succession is divided into two lithostratigraphic units, the Voznuevo Member and the Boñar Formation, which represent fluvial, shoreface, intertidal, subtidal and open‐shelf sedimentary environments. Regional seismic interpretation and sequence stratigraphic analysis have allowed the study of lateral and vertical changes in the sedimentary record and the definition of third‐order levels of stratigraphic cyclicity. On the basis of these data, the succession can be divided into two second‐order depositional sequences (DS‐1 and DS‐2), incorporating three system tracts in a lowstand to transgressive to highstand system tract succession (LST–TST–HST). These sequences are composed of fluvial systems at the base with palaeocurrents that flowed westward and south‐westward. The upper part of DS‐1 (Late Albian–Middle Turonian) shows evidence of intertidal to subtidal and offshore deposits. DS‐2 (Late Turonian–Campanian) comprises intertidal to subtidal, tidal flat, shallow marine and lacustrine deposits and interbedded fluvial deposits. Two regressive–transgressive cycles occurred in the area related to eustatic controls. The evolution of the basin can be explained by base‐level changes and associated shifts in depositional trends of successive retrogradational episodes. By using isobath and isopach maps, the main palaeogeographic features of DS‐1 and DS‐2 were constrained, namely coastline positions, the existence and orientation of corridors through which fluvial networks were channelled and the location of the main depocentres of the basin. Sedimentation on the Upper Cretaceous marine platform was mainly controlled by (i) oscillations of sea level and (ii) the orientation of Mesozoic faults, which induced sedimentation along depocentres. Copyright © 2013 John Wiley & Sons, Ltd.     

地理信息系统在江苏省公益林分布图制作中的应用

运用地理信息系统(GIS)研制了江苏省公益林分布图,总结了公益林分布图制作的原理、方法、技术路线和特点。为江苏省公益林进行信息化管理奠定了基础,为发展高效林业提供了科学的决策和管理平台。     

Crustal and mantle strengths in continental lithosphere: is the jelly sandwich model obsolete?

The relative importance of the contribution of the lower crust and of the lithospheric mantle to the total strength of the continental lithosphere is assessed systematically for realistic ranges of layer thickness, composition, and temperature. Results are presented as relative strength maps, giving the ratio of the lower crust to upper mantle contribution in terms of crustal thickness and surface heat flow. The lithosphere shows a “jelly sandwich” rheological layering for low surface heat flow, thin to average crustal thickness, and felsic or wet mafic lower crustal compositions. On the other hand, most of the total strength resides in the seismogenic crust in regions of high surface heat flow, crust of any thickness, and dry mafic lower crustal composition.     

Tectonic cycles of the New England Orogen,eastern Australia: A Review

The New England Orogen (NEO), the youngest of the orogens of the Tasmanides of eastern Australia, is defined by two main cycles of compression–extension. The compression component involves thrust tectonics and advance of the arc towards the continental plate, while extension is characterised by rifting, basin formation, thermal relaxation and retreat of the arc towards the oceanic plate. A compilation of 623 records of U–Pb zircon geochronology rock ages from Geoscience Australia, the geological surveys of Queensland and New South Wales and other published research throughout the orogen, has helped to clarify its complex tectonic history. This contribution focuses on the entire NEO and is aimed at those who are unfamiliar with the details of the orogen and who could benefit from a summary of current knowledge. It aims to fill a gap in recent literature between broad-scale overviews of the orogen incorporated as part of wider research on the Tasmanides and detailed studies usually specific to either the northern or southern parts of the orogen. Within the two main cycles of compression–extension, six accepted and distinct tectonic phases are defined and reviewed. Maps of geological processes active during each phase reveal the centres of activity during each tectonic phase, and the range in U–Pb zircon ages highlights the degree of diachronicity along the length of the NEO. In addition, remnants of the early Permian offshore arc formed during extensive slab rollback, are identified by the available geochronology. Estimates of the beginning of the Hunter-Bowen phase of compression, generally thought to commence around 265?Ma are complicated by the presence of extensional-type magmatism in eastern Queensland that occurred between 270 and 260?Ma.     

中国陆域航磁系列图编制与研究进展

航磁图件是地球物理调查基础图件,也是认识地质构造特征的重要参考资料.本文介绍了我国陆域航磁编图概况,总结了陆域航磁调查及数据编图的工作进展,展示了陆域航磁系列编图的重要成果.     

空三加密在数字摄影测量中的精度分析

该文结合章丘市1∶2000地形图绘制项目的具体实践,认为航空摄影测量产品误差来源主要为空三加密这一重要工序,影响空三加密精度的因素主要为：影像质量（分辨率、清晰度、重叠度）、像控点选取及精度、加密点的选取及加密解算方法、加密人员的经验等。找出影响空三加密精度的主要因素及解决办法,结合生产实践解决了1∶2000地形图绘制空三加密精度问题。