Free Essay

A Gis‐Based Reconstruction of Little Ice Age Glacier Maximum Extensions for South Tyrol, Italy

In: Computers and Technology

Submitted By c716563
Words 4089
Pages 17
Research Article

A GIS‐based reconstruction of Little Ice Age glacier maximum extensions for South Tyrol, Italy 5

Christoph Knoll
Department of Geography University of Innsbruck

Hanns Kerschner

Department of Geography University of Innsbruck

Armin Heller
10

Philipp Rastner

15

20

25

30

35

40

Department of Geography Institute for Applied Remote Sensing University of Innsbruck EURAC Bolzano Keywords: Little Ice Age, glacier reconstruction, glacier development, GIS Abstract A reconstruction method of historical glacier topographies and a possibility of the usage of these results are demonstrated in this paper. This reconstruction was accomplished for 310 Alpine glaciers in South Tyrol, Italy. These glaciers are featured with a wealth of different historical (e.g. paintings, photographs and historical maps) and recent data sources (airborne laser scan based digital terrain model and digital orthophotos) that allow the reconstruction of the Little Ice Age maximum extension. These sources are among the best historical and recent documents of glaciers for the mid 19th century. The results of this reconstruction visualize the ongoing climate change in a comprehensive way. The area changes between the time of the Little Ice Age maximum extent (around the year 1850) and the recent glaciation in 2006 amounts in a loss of 182.4 km² or almost 66 %. In the same time the calculated mean equilibrium line altitude for all South Tyrolean glaciers rose approximately by 160 m. Address for correspondence: C. Knoll, Department of Geography, University of Innsbruck, Innrain 52, A ‐ 6020 Innsbruck, Austria. E‐mail: christoph.knoll@uibk.ac.at. 1 Introduction The worldwide downwasting of glaciers since the end of the Little Ice Age (LIA) is one of the most significant facts demonstrating the impact of climate change [IPCC 1995; IPCC 2007]. It shows that glacier changes as a result of global climate change are easy to observe. During the last phase of the Little Ice Age in the mid 19th century the majority of the world's glaciers reached maximum extensions. Among other mountain groups, in the European Alps this can be derived from historical maps, dendrochronology, mapping of the conspicuous glacier forefields and moraines and a wealth of historical evidence [Maisch et al. 1999; Zumbühl and Holzhauser 1988]. In general, available historical records can give a detailed picture of former glacier extents and the fluctuations [Gross 1987; Grove 2004; Grove 2004; Maisch, Wipf, Denneler, Battaglia and Benz 1999; Patzelt 1980]. 1

45

50

55

60

65

70

75

80

The worldwide first glacier inventory has been compiled for the Eastern Alps by Richter [Richter 1888] in the year 1888 based on the 3rd Austro‐Hungarian topographic survey. Apart from many local studies, regional or national inventories in the European Alps such inventories have been compiled within the last decade i.e. by Patzelt and Gross [Gross 1987; Patzelt 1978; Patzelt 1980], Maisch [Maisch et al. 1993; Maisch, Wipf, Denneler, Battaglia and Benz 1999], Paul [Paul 2004; Paul and Andreassen 2007; Paul et al. 2002] and Zemp [Zemp et al. 2007; Zemp et al. 2004]. In Austria, LIA reconstructions have been made by Patzelt [Patzelt 1967; Patzelt 1973] and Gross [Gross 1987]. Of the investigation area LIA reconstructions exist only for two parts, one for the Hinteres Martell Valley in the Ortler – Cevedale Group [Müller 2006] and one for the Rieserferner Group [Damm 1998]. In this paper, we present the methods and results of the reconstruction of the LIA maximum glacier extent for South Tyrol (Italy). It has been recognized that GIS is an important and useful tool for this study providing the means to capture and store information of the glacier extents of the region of South Tyrol and visualize it with "Visual Nature Studio" for further presentations. The spatial glacier extent of the Little Ice Age maximum can be reconstructed with the help of raster data calculated from Airborne Laser Scanning (ALS) point data from 2004/2005, digital orthophotos from 2006, historical maps of the 3rd and 4th Austro‐Hungarian topographic survey ("Franzisco‐Josephinische Landesaufnahme" and "Präzisionsaufnahme") and from historical paintings by Thomas Ender [Ender 1964]. We tried to integrate these data into a geodatabase. Unfortunately some of the historical map data are difficult to access or georeference with the required accuracy. The most reliable archive data source is the 4th topographic survey of the Habsburg Empire which was surveyed from 1896 until 1914. The georeferenced sheets of this survey serve as the principal data source for the detection of vanished glaciers and of glacier extents around the turn of the century. The maps of the 3rd topographic survey of the Austro‐Hungarian Empire were surveyed between 1869 and 1887. During both mapping campaigns, the individual map sheets of South Tyrol were created within a decade. Hence the glacier extent depicted on the maps can be assumed to be contemporaneous. The ALS digital elevation model (DEM) and the orthophotos are of highest resolution and accuracy standards. 2 The Study Area Our study focuses on the glacierized areas of the Italian Autonomous Province of Bozen/Bolzano – South Tyrol. It is located in the north east of Italy and is the border province to Austria and Switzerland. The mountains of South Tyrol are situated south of the alpine main divide. The principle mountain groups are the southern Zillertal Alps, the Dreiherren Group, the Rieserferner Group, the Dolomites, the Ortler – Cevedale Group, Sesvenna Group, the Ötztal Alps, the Texel Group and the Stubai Alps (Figure 1). All of these ranges drain into the river Etsch and subsequently Adriatic Sea. The glaciers along the alpine main ridge (Sesvenna Group, Ötztal Alps, Texel Group, Stubai Alps and Zillertal Alps) are primarily exposed towards the south‐east and south‐west, while the glaciers farther to the south are mostly facing towards the north‐east, north and north‐west.

2

85
Figure 1 Little Ice Age maximum glaciation in South Tyrol, Italy.

3 Used data sources for the reconstruction 3.1 Digital Elevation Model The ALS DEM used in this study is a 2.5 m raster dataset of South Tyrol (see Fig. 2) which is calculated from ALS point data [Wack and Stelzl 2005] with a nearest neighbour interpolation method on the last pulse returns. The initial ALS point dataset was acquired using the "Optech" and the "Terrasys" scanner systems during late summer 2005. The elevation accuracy is 0.4 m below 2000 m a.s.l. and 0.55 m above 2000 m a.s.l. An average point density of 8 points per 25 square meters for areas below 2000 m a.s.l. and 3 points per 25 square meters for areas above 2000 m a.s.l. was achieved. The full information of the collected ALS point data, i.e. information for first pulse, last pulse and intensity, is stored in a separate dataset that has not been released yet.

90

95

100
Langtauferer Ferner, Ötztal Alps. Mapping year 2005.

Figure 2 Clip of Hillshade of the ALS DEM, sheets 12041‐4, 12051‐4, 13041‐4 and 13051‐4, showing the area of

3

105

110

3.2 Digital Orthophotos Survey flights to obtain digital aerial photographs of the whole area of South Tyrol (Fig. 1) were carried out by the company Compagnia Generale Ripreseaeree S.p.A. (Parma, Italy) during summer 2006. The orthophotos (see Fig. 3) are calculated at a scale of 1:10.000; all photographs were taken in natural colour with a CCD‐digital camera. The orthophotos are calculated from scanning stripes with a planimetric resolution specified as 1 pixel (pixel size equal to 0.5 m). The planimetric accuracy as stated by the company is equal to ±2 m. Basic information for the photogrammetric data acquisitions have been recorded during the scanning flight with an integrated GPS. Using the orthophotos as a base layer in a GIS environment we delineated the LIA glacier boundaries as polygons by visual inspection.

115
Figure 3 Clip of orthophoto 1:10.000, sheets 12040, 12050, 13040 and 13050, showing the area of Langtauferer Ferner, Ötztal Alps. Mapping year 2006.

120

125

130

3.3 Historical Topographic Maps For this study we used two different historical map datasets. The first one is the 3rd topographic survey and the second is the 4th topographic survey of the Austro‐Hungarian Empire. Both survey campaigns were designed with the rapid production of maps at a scale of 1:75.000 for the whole Empire in mind. Between the years of 1869 and 1887 the Austro ‐ Hungarian army's “k. u. k. Militärgeographisches Institut” carried out the field survey for the 3rd topographic survey (see Fig. 4). This so‐called "Franzisco‐Josephinische Landesaufnahme" was recorded with the plane‐ table method and drawn at a scale of 1:25.000 using the Joseph Marx Baron of Lichtenstern polyhedron projection. The individual map sheets are hand coloured drawings ("Originalaufnahme"). Altitudes were determined by triangulation and barometers. For various reasons, the content of the maps is occasionally rather poor and inaccurate. This includes especially the warpage of several map sheets, position errors and occasionally the oversimplification of the topography of mountain ranges. The lack of accuracy was mainly due to varying survey methods for the map sheets, lack of experience of the surveying teams in high mountain areas, weather conditions, snow cover and logistical problems, which occasionally 4

135

140

caused a misinterpretation of the topography [Hofstätter 1989; Hofstätter 1989]. As a consequence, georeferencing was considered totally not acceptable. We tried a re‐ georeferencing of the single map sheets with the radial basis function and the piecewise affine method. The results were good but they could not compensate the missing geographic contents. Hence the maps of the 3rd topographic survey were only used to locate glaciers that do not exist anymore.

Figure 4 Clip of the "Sektionsblatt" 1:25.000 of the 3 topographic survey, sheet 5245/4, showing the area of Langtauferer Ferner, Ötztal Alps. Mapping year 1872. (© BEV 2008, T2008/50216). rd 145
Langtauferer Ferner, Ötztal Alps. Mapping year 1910. (© BEV 2008, T2008/50216).

Figure 5 Clip of the "Sektionsblatt" 1:25.000 of the 4th topographic survey, sheet 5245/4 showing the area of

5

150

155

160

165

170

175

180

185

190

In anticipation of hostilities with the Kingdom of Italy, the 4th topographic survey (see Fig. 5) was carried out by the Austro ‐ Hungarian army's “k. u. k. Militärgeographisches Institut” from 1896 to 1914. This so‐called "Präzisionsaufnahme" was also drawn and coloured by hand at a scale of 1:25.000 using the Joseph Marx Baron of Lichtenstern polyhedron projection. However, in consideration of the weaknesses of the 3rd topographic survey, terrestrial stereo‐ photogrammetry was used as the state‐of‐the‐art method. The geodetic base was the MGI (Militärgeographisches Institut) Ferro datum based on the Bessel 1841 ellipsoid and the Gauss‐ Krueger projection. This historical map set is characterized by higher spatial resolution and more details in the map contents with a more accurate georeferencing than the older map set of the 3rd topographic survey. Information about applied methods, mapping rules and used definitions are summarized by Hofstätter (1989a, 1989b). Digital copies of the hand‐drawn original sheets 1:25.000 were used for this work. Compared to modern practices of map survey and production, the accuracy of the maps is supposed to be lower but was at the highest level at the time of recording and is the best historical data that is accessible for the whole South Tyrolean area. 4 Methods Reconstructing the Little Ice Age maximum extent of glaciers requires detailed geomorphologic mapping via high resolution DEMs, orthophotos and field work. This requires sufficient geomorphologic evidence, usually lateral and terminal moraines and trimlines, to allow the reconstruction of the former glacier topography. In the case of the LIA maximum moraines in the investigation area, field evidence and documentary evidence in the ablation areas is so conspicuous that misinterpretations of landforms by a trained glacial‐geomorphologist who is familiar with the examination area can be practically excluded. In contrast to the ablation areas the reconstruction in the accumulation areas is more difficult because there almost no moraines occur and the reconstruction is only based on the experience of the surveyor and the calculated heights [Maisch, Wipf, Denneler, Battaglia and Benz 1999; Patzelt 1967; Patzelt 1973]. Careful consideration of the field evidence is critical for evaluating the timing and extent of glacier advances. The exact year of the maximum extent is only known for a few large valley glaciers like Sulden Ferner and Langtauferer Ferner. However, the temporal uncertainty of the maximum is only within a range of a few years. For the reconstruction of the Little Ice Age glacier topography we used the interpretation of the new ALS DEM and orthophotos combined with field inspection of selected sites to reconstruct area and volume changes and the equilibrium line altitude (ELA). The calculation and reconstruction is based on the interpretation of the 3rd and 4th Austro‐ Hungarian topographic survey to find glaciers that do not exist anymore as well as on the interpretation of the hillshade of the ALS DEM and the orthophotos. The transformation and visualization of the 2D data into 3D data with ESRI ArcScene and Visual Nature Studio gave additional useful insights into the maximum extent. Field work formed the basis for closing the gaps. For the contour line reconstruction a cartometric interpretation of the generated 100 m contour lines of the ALS DEM was combined with shear stress calculations of the glacier tongue. The shear stress τ was derived from a mean slope over two 100 m height intervals. In a first 6

195

approximation, the quantity of τ depends on the slope of the glacier bed. Then the ice thickness is [Paterson 2001] α for the contour line reconstruction, where τ is between 50 ‐ 300 kPa depending on the steepness of the glacier, ρ is the density of glacier ice [900 kgm‐³] and g is the acceleration due to gravity [9.81 ms‐2] [Paterson 2001]. The areal extent of the glaciers is described by closed polygons. In the case of the three digitized glacial stages (LIA maximum, 1997 and 2006) altitude data for each vertex of the polygons was interpolated from the respective DEM. In order to be consistent with the computed DEMs the photogrammetrically derived z‐values of the polygons of the 1997 survey were also replaced by the respective height values of the DEM. 5 Quantification of glacier retreat At the LIA maximum, 310 glaciers existed in South Tyrol. The three largest glaciers were at the time of maximum extension Übeltalferner (Stubai Alps, 12.41 km²), Zufall Ferner (Ortler– Cevedale Group, 14.88 km²) and Suldenferner (Ortler – Cevedale Group, 10.18 km²). 13 glaciers (4.2 per cent) were larger than 4 km² and 238 (76.8 per cent) out of the 310 were smaller than 1 km². The total area of the South Tyrolean glaciers was 276 km² (Table 1). It is now possible to determine the area and volume loss of glaciers since the LIA maximum at about 1850 for the first time for the entire South Tyrolean mountains. Table 1 gives an overview of the glacierized area at the time of maximum glaciation during LIA and the recent glacier area of 2006 [Knoll and Kerschner 2009 (submitted)] in the respective mountain ranges. It shows that about two thirds of the glacier area was lost during the last approximately 150 years. The equilibrium line altitude was calculated for each glacier and a mean value for each of the mountain ranges (see Figure 1). The accumulation area method with an accumulation area ratio (AAR) of 0.67 is used for this purpose, i.e. the accumulation area is 67% of the total glacier surface, was used for the calculation of the ELA change since the time of maximum extension [Gross et al. 1978]. A steady‐state of the South Tyrolean glaciers was estimated for both times whereas a steady‐state in 2006 is not to be expected. The effective rise of the ELA was larger than the mean value of 160 m (Table 1), because in 2006 and the preceding years glaciers were clearly out of balance. A value of approximately 250 m, as it can be derived in the Zillertal Alps is most probably more realistic, because glaciers there are mainly situated in small cirques where ice reacts quickly to climatic changes. ρ h

τ

200

205

210

215

220

225

7

230
Table 1: Area and ELA changes between LIA maximum glaciation and 2006.

6 Visualization of the glacier development since the end of Little Ice Age 235
6.1 Data preparation Based on digitised contour lines a digital elevation model with a resolution of 2.5 m has been created in ENVI 4.5 (Convert contours to DEM – linear technique). Subsequently, the difference to the more recently released ALS DEM 2006 of South Tyrol was calculated. The obtained result was a signed floating ‐ tif imagery that had to be separated in two different files, one with only positive integer values and another with only negative integer values. This is, because the visualization program Visual Nature Studio 2.8 is only able to read 8bit unsigned integers for its function “Area Terraffector”. 6.2 Data visualisation The ALS DEM of South Tyrol and the digital orthophotos were imported into the program Visual Nature Studio 2.8 for data visualisation. Additionally, the difference models (both the files positive and negative values) were imported and connected to the “Area Terraffector” function to modify the terrain. As a second last step the white colour was allocated to the glacier body in order to achieve a more realistic impression. Finally, a historic image as well as a recent image from the same position was generated to allow direct comparison.

240

245

250
(right, 2006) extension.

Figure 6 and 7: Visualisation of Langtaufererferner, Ötztal Alps/Italy for its maximum (left, about 1830) and recent

255

8

260

265

270

275

280

285

290

295

7 Discussion and Conclusions Recent and historic remote sensing technologies combined with suitable reconstruction techniques can contribute to a reconstruction of LIA maximum glacier extents and recent Alpine glaciers topographies. This study is focused on the historic glaciers where a realistic reconstruction of LIA glaciers and the corresponding contour lines was achieved. In the beginning we tried a reconstruction based on historical map sets but, because of problems in georeferencing and topographic contents, these maps of the 3rd and 4th Austro‐Hungarian topographic survey have not been taken into account. In the next step the work was focused on the reconstruction of the LIA maximum extents based on the interpretation of digital orthophotos of 2006 and the ALS DEM of 2005. A detection of lateral and terminal moraines would be half‐automatically possible but will give partly incorrect results as moraines are often disconnected or have been eroded during approximately the last 150 years. Also a manual detection is only possible if the adapter is a trained glacial‐ geomorphologist who is familiar with the examination. A manual detection method for the moraines was chosen for the present LIA reconstruction. This new approach, which is based on ALS DEMs and orthophotos, provides a geometrical monitoring and verification of the reconstructed results. Former reconstructions have been based mostly on historical or older topographical maps where the analysis of the historic glaciological topographies was drawn with ink or pencil on transparent paper. The analysis of these results was accomplished with mechanical planimeters. Today comprehensive topographic fundamentals allow more precise investigations. Glacier topographies can be reconstructed easier with much higher precision and accuracy because of higher resolutions of the input data. The main advantage of this approach is the doubtless, well‐defined and efficient operation method providing a good basis for further analysis of the changed climatic conditions since the end of LIA. Acknowledgements The project is funded by the PhD scholarship of the University of Innsbruck and by the Faculty for Geo‐ and Atmospheric Sciences, University of Innsbruck. The Authors want to thank Gernot Patzelt, Georg Kaser, Michael Kuhn, Astrid Lambrecht, Jakob Abermann and the Glaciological Seminar Innsbruck (MSc, PhD and PostDocs) of the University of Innsbruck and the Austrian topographic survey (Bundesamt für Eich‐ und Vermessungswesen BEV) for the maps of the 3rd and 4th topographic survey (© BEV 2008, T2008/50216). References DAMM, B. 1998. Der Ablauf des Gletscherrückzuges in der Rieserfernergruppe (Tirol) im Anschluss an den Hochstand um 1850. Zeitschrift für Gletscherkunde und Glazialgeologie 34, 141‐159. ENDER, T. 1964. Katalog zur Ausstellung "Thomas Ender" der graphischen Ausstellung der Albertina. Albertina Vienna, Vienna. GROSS, G. 1987. Der Flächenverlust der Gletscher in Österreich 1850–1920–1969. Zeitschrift für Gletscherkunde und Glazialgeologie 23(2), 131‐141. 9

300

305

310

315

320

325

330

335

340

GROSS, G., KERSCHNER, H. and PATZELT, G. 1978. Methodische Untersuchungen über die Schneegrenze in alpinen Gletschergebieten. Zeitschrift für Gletscherkunde und Glazialgeologie 12(2), 223‐251. GROVE, J.M. 2004. Little ice ages : ancient and modern. Routledge, New York. GROVE, J.M. 2004. Little ice ages : ancient and modern. Routledge, New York. HOFSTÄTTER, E. 1989. Beiträge zur Geschichte der Österreichischen Landesaufnahmen: Ein Überblick der topographischen Aufnahmeverfahren, deren Ursprünge, ihrer Entwicklungen und Organisationsformen der vier österreichischen Landesaufnahmen. Bundesamt für Eich‐ und Vermessungswesen BEV, Vienna. HOFSTÄTTER, E. 1989. Beiträge zur Geschichte der Österreichischen Landesaufnahmen: Ein Überblick der topographischen Aufnahmeverfahren, deren Ursprünge, ihrer Entwicklungen und Organisationsformen der vier österreichischen Landesaufnahmen. Bundesamt für Eich‐ und Vermessungswesen BEV, Vienna. IPCC 1995. Climate Change 1995: The Science of Climate Change. Contribution of Working Group I to the Second Assessment of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge. IPCC 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, S. SOLOMON, D. QIN, M. MANNING, Z. CHEN, M.C. MARQUIS, K. AVERYT, M. TIGNOR and H.L. MILLER Eds. Intergovernmental Panel on Climate Change, Cambridge, New York. KNOLL, C. and KERSCHNER, H. 2009 (submitted). A glacier inventory for South Tyrol, Italy, based on airborne laser scanner data. Annals of Glaciology 53. MAISCH, M., BURGA, C.A. and FITZE, P. 1993. Lebendiges Gletschervorfeld : von schwindenden Eisströmen, schuttreichen Moränenwällen und wagemutigen Pionierpflanzen im Vorfeld des Morteratschgletschers Zurich. MAISCH, M., WIPF, A., DENNELER, B., BATTAGLIA, J. and BENZ, C. 1999. Die Gletscher der Schweizer Alpen. Gletscherhochstand 1850, Aktuelle Vergletscherung, Gletscherschwund Szenarien, Schlussbericht NFP31. VdF Hochschulverlag, Zurich. MÜLLER, S. 2006. Gletscherstände und Klimawandel im Hinteren Martelltal, Südtirol. In Fakultät für Forst‐ und Umweltwissenschaften University of Freiburg, Freiburg im Breisgau. PATERSON, W.S.B. 2001. The Physics of Glaciers. New York. PATZELT, G. 1967. Die Gletscher der Venedigergruppe ‐ Die Geschichte der Schwankungen seit Beginn der postglazialen Wärmezeit. In Department of Geography University of Innsbruck, Innsbruck. PATZELT, G. 1973. Die neuzeitlichen Gletscherschwankungen in der Venedigergruppe (Hohe Tauern, Ostalpen). Zeitschrift für Gletscherkunde und Glazialgeologie 9, 5‐57. PATZELT, G. 1978. Der Österreichische Gletscherkataster. In Almanach ’78 der Österreichischen Forschung, Vienna, 129‐133. PATZELT, G. 1980. The Austrian glacier inventory: status and first results. IAHS. PAUL, F. 2004. The new Swiss glacier inventory 2000 ‐ Application of remote sensing and GIS. In Department of Geogrpahy University of Zurich, Zurich, 194.

10

345

350

355

360

PAUL, F. and ANDREASSEN, L.M. 2007. A new glacier inventory for the Svartisen area (Norway) from Landsat ETM+: Methodological challenges and first results. In Proceedings of the Workshop and GLACIODYN (IPY) meeting, Pontresina, 15‐18 January 2007 2007. PAUL, F., KÄÄB, A., MAISCH, M., KELLENBERGER, T.W. and HÄBERLI, W. 2002. The new remote‐ sensing‐derived Swiss Glacier Inventory: I. methods. Annals of Glaciology 34, 355‐361. RICHTER, E. 1888. Die Gletscher der Ostalpen. Engelhorn, Stuttgart. WACK, R. and STELZL, H. 2005. Laser DTM generation for South‐Tyrol and 3D‐Visualization. In Proceedings of the ISPRS Workshop Laser scanning 2005, G. VOSSELMAN and C. BRENNER Eds., Enschede, the Netherlands, 48‐53. ZEMP, M., PAUL, F., HOELZLE, M. and HÄBERLI, W. 2007. Glacier fluctuations in the European Alps 1850–2000: an overview and spatio‐temporal analysis of available data. In The darkening peaks: Glacial retreat in scientific and social context, B. ORLOVE, E. WIEGANDT and B. LUCKMANN Eds. University of California Press. ZEMP, M., PAUL, F., HOELZLE, M. and HAEBERLI, W. 2004. Alpine glacier fluctuations 1850‐ 2000: overview and spatio‐temporal analysis of available data and its representativity. In International and Interdisciplinary Workshop on Mountain Glaciers and Society, October 6‐8, 2004., Wengen, Switzerland. ZUMBÜHL, H.J. and HOLZHAUSER, H. 1988. Alpengletscher in der Kleinen Eiszeit. In Die Alpen. Zeitschrift des Schweizer Alpen‐Club SAC, 129‐322.

11…...

Similar Documents

Premium Essay

South

...History * The early inhabitants * The early colonial period * The British colonial era * The mineral revolution * The Anglo-Boer/South African War (October 1899 – May 1902) and its aftermath * Segregation * Apartheid * The end of apartheid * The First Decade of Freedom * Into the Second Decade of FreedomThe early inhabitantsThe discovery of the skull of a Taung child in 1924; discoveries of hominid fossils at Sterkfontein caves, a world heritage site; and the ground-breaking work done at Blombos Cave in the southern Cape, have all put South Africa at the forefront of palaeontological research into the origins of humanity. Modern humans have lived in the region for over 100 000 years.The latest discovery is a new species of hominid, Australopithecus sediba, almost two million years old. It was discovered in the Cradle of Humankind World Heritage Site, 40 kilometres from Johannesburg, South Africa in 2010. The small, mobile bands of Stone-Age hunter- gatherers, who created a wealth of rock art, were the ancestors of the Khoikhoi and San of historical times. The Khoikhoin and San (the "Hottentots" and "Bushmen" of early European terminology), although collectively known as the Khoisan, are often thought of as distinct peoples.The former were those who, some 2 000 years ago, adopted a pastoralist lifestyle herding sheep and, later, cattle. Whereas the hunter-gatherers adapted to local environments and were scattered across the subcontinent, the herders sought......

Words: 14873 - Pages: 60

Premium Essay

Melting of Ice Glaciers

...The melting of ice glaciers is considered to be a normal act of nature. The real problem occurs when “the snow replenishing it is less than the melted water.” (Mathias, 2011). This problem is occurring with the majority of glaciers around the world, with the size of the glaciers reducing causing an increase in the sea water levels. The primary culprit for the sudden melting of ice glaciers is the rapid industrialization and the burning of fossil fuels taking place. There are many negative effects on the earth because of the rapid melting of ice glaciers but the most prominent ones are global warming, shortage in fresh water and the rise in sea level. The human population has taken action to try and reduce the severity of these effects, and have been successful in doing so, but they are still very present. Global warming is a concern that is well-known by the majority of our population and a mutual effort of several countries to reduce the overall release of pollution and greenhouse gases was carried out through a contract called the “Kyoto Protocol.” This is one good example of the awareness of the issues that we as a planet are facing, and how we have tackled these severe issues. Glacier melting is on the rise and the effects, as a result, are becoming more serious which is why it is worth investigating ways in which these situations can be mitigated. The relationship between the melting ice glaciers and global warming is best described as a feedback loop, which defined......

Words: 1509 - Pages: 7

Premium Essay

Agricultural Extension in India

...Agricultural Extension in India Booklet No. 380 Agricultural Extension Education: AEES-4 Content Preface I. Introduction II. Pre-Independence Era III. Post-Independence Era IV. Motivation V. Extension Methodology in India VI. Training of Extension Personnel VII. Extension Organization in India VIII. Extension and Women IX. Extension and Rural Youth X. Emerging Thoughts in Extension Preface Agricultural extension is an educational process which has its goal to help the rural people to build a better life by conveying the useful and needed information at appropriate time. It is essential for agricultural development. It plays a major part in technology transfer to the rural areas. Though the concept of agricultural extension started in early 16th century but the actual functioning started only after the second world war. Dr. K. T. Chandy, Agricultural & Environmental Education I. Introduction Agricultural extension is a branch of agriculture which assists the farmers to bring about continuous improvement in their physical, economic and social well being through individual and cooperative efforts. In other words, it helps in the development of an individual and the village community as a whole. It makes available to the farming community the scientific and technical information, training and guidance to solve the problems in agriculture including animal husbandry, gardening, horticulture, silviculture, agricultmal......

Words: 7605 - Pages: 31

Premium Essay

Facial Reconstructions

...Forensic Facial Reconstructions Samantha McAnally CRMJ430 April 20, 2013 Abstract This paper will focus mainly on the history and the various techniques that forensic facial reconstruction has to offer. It will also go over some problems or an issue that is process has faced over the years. The Daubert Standard will discuss and how facial reconstruction was allowed as evidence thru this standard. I will go over all the periods of time that facial reconstruction was used. Computerized and Clay reconstruction will be discussed and how they have help investigators solved current and cold case crimes. Forensic Facial Reconstruction Forensic facial reconstruction is the method of restoring the appearance of a person (whose identity is frequently not recognized) from their skeletal remnants through a combination of creativity, forensic science, anthropology, osteology, and anatomy. The situation can also display what an individual would look like as an adult if they were abducted or gone missing as adolescents. In this paper, we will discuss the different approaches that can be used in facial reconstruction from computerized techniques to sketch artist techniques. The fortitude of forensic facial reconstruction is to yield an image from a skull that suggests an adequate resemblance of the thriving individual that the situation will assist in the proof of identity of the skeletal remnants while there are not any additional resources accessible. Finding skeletons......

Words: 2024 - Pages: 9

Free Essay

Cultural Analysis of Italy

...Cultural Analysis of Italy I. INTRODUCTION Italy is one of the most crowded nations in Europe with a population of roughly 58.2 million. As country, it has much to offer its citizens and visitors. The capital of Italy is Rome (also known as the Eternal City) and is almost 3,000 years old. It has been the capital since 1871 and is home to the Dome of St. Peter's, the Sistine Chapel, the Coliseum, and the famous Trevi Fountain. They are well known for their culture and food, along with their easily recognizable shape as a boot. They are passionate about many things, including their food. When McDonald's opened in 1986 in Rome, food purists outside the restaurant gave away free spaghetti to remind people of their culinary heritage. The richness of its past and the 'live-life-to-the-fullest' attitude combine to make Italy a must-see travel destination. II. RELEVANT HISTORY Evidence of civilization has been found on the Italian peninsula dating far into pre-history. Thousands of rock drawings discovered in the Alpine regions of Lombardy date from around 8,000 BC. There were sizable settlements throughout the Copper Age (37th to 15th century BC), the Bronze Age (15th to 8th century BC) and the Iron Age (8th to 5th century BC). In the north of Italy, the Etruscan culture took hold around 800BC, while Greeks settled in southern Italy from 700 to 600BC, namely in Apulia, Calabria and Sicily (then known as Magna Graecia). The Roman Empire (5th Century BC to 5th Century AD)......

Words: 5559 - Pages: 23

Free Essay

Will Humans Be Able to Survive the Next Ice Age?

...term survival? Submitted by: Andrew Jara Submitted to: Heidi White Course: AST 251H1 Due Date: March 12, 2013   1  As time passes, the Earth and all its inhabitants grow older, one must ask that as the number of inhabitants are increasing and the amount of resources decreasing, whether or not the human race will be able to withstand extinction. The parameters of human intelligence can be used to define and determine the possibility of this outcome. Humans are believed to have the title of being the most dominant and intelligent species on the face of the Earth, but there is much competition for that title today and arguments arise within the scientific community. Humans believe that they are separated from all other species based on the concept of intelligence and how they have used intelligence to their advantage to create language, technology and many other things to ultimately establish themselves as a successful species. In order to actually prove that humans rightfully deserve that title, one must delve into the debate of intelligence to clarify the meaning and understanding of intelligence. This will provide evidence to the argument on whether or not the human species will be viable in the long-term. In the Merriam-Webster online dictionary, intelligence is defined as the ability to collect and apply certain knowledge and information from the external environment to different situations1. Although this is a brief and vague definition, certain scientists......

Words: 2831 - Pages: 12

Free Essay

Glaciers

...Glaciers by Crystal Sweet Rasmussen College Author’s Note This paper is being submitted for Introduction to Geology course at Rasmussen College to Dr. Nikki Strong on June 16, 2013, by Crystal Sweet. When you think fresh water what comes to mind? Perhaps a bottle of water or a stream that is so clear you can see the bottom, did you ever think of glaciers? Glaciers actually store up to 75% of our fresh water (NSIDC, 2013). This natural occurrence has happened many years and at one time it actually had covered up to 32% (NSIDC, 2013) of the earth which occurred when there was an ice age. Figure [ 1 ]: Layers of Glaciers (http://whatdoino-steve.blogspot.com/2012/03/niveolian-art.html) Figure [ 1 ]: Layers of Glaciers (http://whatdoino-steve.blogspot.com/2012/03/niveolian-art.html) Glaciers are all over the world the only place that doesn’t have glaciers is Australia. You may not believe it but even Africa has glaciers. Glaciers start out as snowflakes but need to have the right environment to grow into a glacier. Most are found in areas that have large amounts of snow fall in the winters and the warm seasons stay cool so the snow doesn’t melt completely. So the snow from the winter starts to melt but does not completely melt, then it forms into ice and new snowfalls on the layer of ice that winter; this circle keeps happening and the glaciers grow and eventually start to move because of its own weight. They can be as small as a football field or as enormous as......

Words: 2470 - Pages: 10

Free Essay

Comparative Phylogeography of Freshwater Habitats in Southern Australia: Using Palaeodrainage Reconstructions to Investigate Population Structure and Historic Population Connectivity

...Comparative Phylogeography of Freshwater Habitats in Southern Australia: Using Palaeodrainage Reconstructions to Investigate Population Structure and Historic Population Connectivity Sarah Jackson A thesis submitted in partial fulfilment for the degree of Bachelor of Animal and Veterinary Bioscience with Honours Department of Genetics School of Molecular Science La Trobe University October, 2011 Contents Abstract ........................................................................................................................... iii 1. Introduction .................................................................................................................. 1 1.1 Phylogeography....................................................................................................... 1 1.2 Palaeodrainage........................................................................................................ 4 1.3 Background on Study Species .................................................................................. 6 1.4 Aims and Hypothesis ............................................................................................... 8 2. Materials and Methods ............................................................................................... 10 2.1 Locations ............................................................................................................... 10 2.2 Expectations of Hypothesis.....................................

Words: 6481 - Pages: 26

Premium Essay

Melting Ice Glaciers

...Melting of Ice Glaciers In: Science Melting of Ice Glaciers The melting of ice glaciers is considered to be a normal act of nature. The real problem occurs when “the snow replenishing it is less than the melted water.” (Mathias, 2011). This problem is occurring with the majority of glaciers around the world, with the size of the glaciers reducing causing an increase in the sea water levels. The primary culprit for the sudden melting of ice glaciers is the rapid industrialization and the burning of fossil fuels taking place. There are many negative effects on the earth because of the rapid melting of ice glaciers but the most prominent ones are global warming, shortage in fresh water and the rise in sea level. The human population has taken action to try and reduce the severity of these effects, and have been successful in doing so, but they are still very present. Global warming is a concern that is well-known by the majority of our population and a mutual effort of several countries to reduce the overall release of pollution and greenhouse gases was carried out through a contract called the “Kyoto Protocol.” This is one good example of the awareness of the issues that we as a planet are facing, and how we have tackled these severe issues. Glacier melting is on the rise and the effects, as a result, are becoming more serious which is why it is worth investigating ways in which these situations can be mitigated. The relationship between the melting ice glaciers and global......

Words: 376 - Pages: 2

Free Essay

Italy

...I HISTORY OF ITALY History The migrations of Indo-European peoples into Italy probably began about 2000 B.C. and continued until 1000 B.C. From about the 9th century B.C. until it was overthrown by the Romans in the 3rd century B.C. , the Etruscan civilization was dominant. By 264 B.C. , all Italy south of Cisalpine Gaul was under the leadership of Rome. For the next seven centuries, until the barbarian invasions destroyed the western Roman Empire in the 4th and 5th centuries A.D. , the history of Italy is largely the history of Rome. From 800 on, the Holy Roman Emperors, Roman Catholic popes, Normans, and Saracens all vied for control over various segments of the Italian peninsula. Numerous city-states, such as Venice and Genoa, whose political and commercial rivalries were intense, and many small principalities flourished in the late Middle Ages. Although Italy remained politically fragmented for centuries, it became the cultural center of the Western world from the 13th to the 16th century. Etymology The assumptions on the etymology of the name "Italia" are very numerous and the corpus of the solutions proposed by historians and linguists is very wide. According to one of the more common explanations, the term Italia, from Latin: Italia, was borrowed through Greek from the Oscan Víteliú, meaning "land of young cattle" (cf. Lat vitulus "calf", Umbvitlo "calf").The bull was a symbol of the southern Italic tribes and was often depicted goring the Roman wolf as a defiant......

Words: 4042 - Pages: 17

Premium Essay

Alpine Glacier Reconstruction

...UNIVERSITY OF SOUTH ALABAMA Last Time Glaciers and Glacial Mechanics • • Types of glaciers (alpine) Formation of glacial ice • Movement of ice GY 301: Geomorphology Lecture 22: Glacial Geomorphology 1: Alpine Glaciers http://www.roberts-1.com/t/s07 Glaciers Glaciers are thick masses of ice that originate on land through the accumulation of snow. Glaciers Glaciers are thick masses of ice that originate on land through the accumulation of snow. Glaciers form through a 3 step process Snow Firn Glacial Ice All that is required is for more snow to fall in the cold winter months than melts in the warm summer months. http://media-cdn.tripadvisor.com/media/photo-s/01/25/4a/ee/in-the-mountains-above.jpg http://www.ig.utexas.edu Alpine Glaciers Alpine or Valley Glaciers (Zone of Accumulation; Zone of Wasting/Ablation, Calving,) Ice Movement Ice moves down slope from the zone of accumulation to the zone of ablation due to a combination of plastic flow and basal slip. http://www.scienceclarified.com/images/uesc_05_img0282.jpg http://stloe.most.go.th/html/lo_index/LOcanada3/305/images/5_2.jpg http://nevis.k12.mn.us/academics/science/glacier_hor_profile1.jpg 1 Ice Movement Ice moves down slope from the zone of accumulation to the zone of ablation due to a combination of plastic flow and basal slip. Slip Geological Effects of Glaciers Ice exerts tremendous erosive force on bedrock forming unique geomorphologic features and transporting...

Words: 789 - Pages: 4

Free Essay

Glacier

...Date: Glacier Glacier, any large mass of perennial ice that originates on land by the recrystallization of snow or other forms of solid precipitation and that shows evidence of past or present flow. Exact limits for the terms large, perennial, and flow cannot be set. Except in size, a small snow patch that persists for more than one season is hydrologically indistinguishable from a true glacier. One international group has recommended that all persisting snow and ice masses larger than 0.1 square kilometre (about 0.04 square mile) be counted as glaciers. Glaciers are classifiable in three main groups: (1) glaciers that extend in continuous sheets, moving outward in all directions, are called ice sheets if they are the size of Antarctica or Greenland and ice caps if they are smaller; (2) glaciers confined within a path that directs the ice movement are called mountain glaciers; and (3) glaciers that spread out on level ground or on the ocean at the foot of glaciated regions are called piedmont glaciers or ice shelves, respectively. Glaciers in the third group are not independent and are treated here in terms of their sources: ice shelves with ice sheets, piedmont glaciers with mountain glaciers. A complex of mountain glaciers burying much of a mountain range is called an ice field. Distribution of glaciers A most interesting aspect of recent geological time (some 30 million years ago to the present) has been the recurrent expansion and contraction of the world’s ice......

Words: 927 - Pages: 4

Premium Essay

Age Discrimination and Age-Based Rationing of Health Care

...Age Discrimination and Age-Based Rationing of Health Care Crystal LaShae Hunter HMP671 – Ethics in Health Care - Fall II 2015 (Week 6) Valparaiso University Author Note: “I have neither given, received, nor have I tolerated other's used of unauthorized aid." Age Discrimination and Age-Based Rationing of Health Care Health care as a social good, requires a tremendous amount of a nation’s expenditures; and health care is not the only social good that a nation must consider, there are also the social goods of defense, education, public health, and infrastructure, to name a few. In the United States alone, the percentage of the GDP spent on health care over a three year period, from 2011-2013, averaged 17.066% (17.1%, 17.0%, 17.1%, each respective year) (The World Bank Group, Inc, 2015). In retrospect, despite the passing and subsequent implementation of the Affordable Care Act in 2010, with the final aspects of the bill effective January 1, 2015, the ever-rising cost of health care may never truly subside, as the nation’s baby boomers continue to age and subsequent chronic conditions often associated with aging such as coronary artery disease, diabetes, and certain cancers increase with the aging population. In fact, according to Centers for Medicare and Medicaid Services (2015), Medicare accounted for 20% of total US health care expenditure in 2014, growing 5.5% and expected to “accelerate after 2015” in direct correlation to the expected increases in use of medical...

Words: 6513 - Pages: 27

Premium Essay

How Global Warming May Cause the Next Ice Age

...How Global Warming May Cause the Next Ice Age... If you look at a globe, you'll see that the latitude of much of Europe and Scandinavia is the same as that of Alaska and permafrost-locked parts of northern Canada and central Siberia. Yet Europe has a climate more similar to that of the United States than northern Canada or Siberia. Why? The warmth in Europe is the result of ocean currents that bring warm surface water up from the equator into northern regions that would otherwise be so cold that even in summer they'd be covered with ice. The current of greatest concern is often referred to as "The Great Conveyor Belt," which includes what we call the Gulf Stream. The Great Conveyor Belt, while shaped by the Coriolis effect of the Earth's rotation, is mostly driven by the greater force created by differences in water temperatures and salinity. The North Atlantic Ocean is saltier and colder than the Pacific, the result of it being so much smaller and locked into place by the Northern and Southern American Hemispheres on the west and Europe and Africa on the east. As a result, the warm water of the Great Conveyor Belt evaporates out of the North Atlantic leaving behind saltier waters, and the cold continental winds off the northern parts of North America cool the waters. Salty, cool waters settle to the bottom of the sea, most at a point a few hundred kilometers south of the southern tip of Greenland, producing a whirlpool of falling water that's 5 to 10 miles across.......

Words: 1133 - Pages: 5

Free Essay

Glaciers

...Glaciers A glacier is a huge mass of ice on land or floating in the sea next to land. Glaciers move extremely slowly. Regions with continuous snowfall and freezing temperatures are the perfect place for glaciers. It is so cold that when a snowflake hits the ground it does not melt, it combines with other snowflakes to form large grains of ice. As it snows more, the weight and pressure squeeze these grains of ice together to form a glacier. Most glaciers form in high mountain regions such as the Himalayas or the Alps. Glaciers are also found in Antarctica, Greenland, Iceland, Canada, Alaska, and the Andes of South America. Glaciers cover about 10% of Earths land and hold around 77% of Earths freshwater. There are two types of glaciers. They are alpine and continental. Most glaciers that form in a mountain are alpine glaciers. There are several types of alpine glaciers. Crique: A crique is a bowl shped hollow at the head of a valley. Inside there is a snowfield, this is the place where snow accumulates to form a cirque glacier. Valley: A glacier that is in an area eroded by a stream is called a valley glacier. Piedmont: A piedmont glacier is formed when multiple vally glaciers come together as a large stretch of flat line. Tidewater: A tidewater glacier is a glacier that meets the sea. A process called Calving occurs when a piece of the glacier breaks off into the sea forming a large mass of floating ice known as an iceburg...

Words: 486 - Pages: 2