Evangelos Livieratos

On the Study of the Geometric Properties of Historical Cartographic Representations

Abstract The long but partial and still open question of the geometric and projective characteristics and properties of early cartographic representations is revisited in view of the advancements in digital analytical and visual technologies that are now offered in a “part and parcel” operational environment, allowing a level of interactivity almost unthinkable even in the recent past. In this new technology frame, the geometric study of early maps is treated analytically via a typical two-dimensional comparison with relevant modern map counterparts or georeference. By bringing in the early map with a one-to-one correspondence to its modern reference, the comparison retains all those proper transformational steps that result in the visualization of map differences and, thus, the study of the geometric and projective properties of early maps. To illustrate the proposed process, two indicative examples are treated, related to two distinct schematic typologies of early maps: (1) a georeferenced map of the Pt...

Applications of strain criteria in cartography

SummarySome of the most commonly used map projections, are analysed from the viewpoint of the deformation introduced, when the objective spherical surface is mapped into a plane. After a short theoretical account, formulae for the computation of dilatation and maximum shear strain are given for various projections. These two invariant quantities may be used as criteria for the choice of a map projection in addition to the traditional criteria of conformality, equivalence, etc.

Pre-seismic responses of underground water level and temperature concerning a 4.8 magnitude earthquake in Greece on October 20, 1988

Abstract It is widely known that level and temperature changes of the underground waters are associated with earthquake activity. In this paper we present results obtained from a simple and indeed inexpensive underground water level and temperature monitoring network established for the first time in a seismic zone of Greece. Sharp changes in the underground water level and temperature have been recorded mainly as pre-seismic events of the earthquake of magnitude 4.8, which occurred in the area of the network on October 20, 1988.

The influence of correlations in computing crustal strains from trigonometric network results

Abstract A variance-covariance analysis is made concerning the crustal strain parameters deduced from triangulation results. The coordinate difference method is treated, the algorithm of the analysis being valid for either free or constrained network adjustments. The importance of the correlations entering into the calculation of the standard deviations of strains is emphasized, showing how even poor geodetic results can be sometimes useful in crustal strain analyses.

Techniques and Problems in Geodetic Monitoring of Crustal Movements at Tectonically Unstable Regions

The possibilities and limitations of the contribution of geodetic methods for the monitoring of secular crustal dynamics are discussed in view of plate tectonics and of local crustal deformations related with the earthquakes. Topics concerning the calculation of long-term strain frcm geodetic results are stressed in connection with short-term strain information obtained by geophysical instrumentation and reliability problems associated with the design of geodetic operations are as well underlined. A brief discussion on the necessity of applying geodetic methods as integrating factor for crustal deformation studies as far as the Hellenic tectonically anstable region is concerned, concludes the paper.

The Matteo Ricci 1602 Chinese World Map: the Ptolemaean echoes

ABSTRACT The World Map in Chinese, by Matteo Ricci (1602 version) is of great importance for both the Chinese and the European cartographic heritage – not only for its cartographic contexts but also as an example of the cultural impact a map could have in the interaction of the European cartography with other civilisations. In this paper, the multichannel echoing of Ptolemaean cartography in the Ricci’s map is underlined with respect to fundamental map-elements. The Ptolemy’s echoing in Ricci’s map and the meta-Ptolemy advances in the ‘Euro-Mediterranean’ school of cartography embrace the Ricci Chinese map in its legacy. The established belief on the influence of the ‘Euro-Atlantic’ counterpart on Ricci’s map seems a rather weak standpoint.

Revisiting sixteenth-century oval maps with a cartographic strain analysis

ABSTRACT A recent research on Matteo Ricci’s 1602 Chinese World Map raised, among other issues, the question of the oval graticule used before as the projection reference of the map representation. Here, we go back to the origin of the oval graticules, which almost dominated the imaging of the sixteenth-century cartography from the Contarini-Rosselli’s map in the earliest of the century to the Ortelius and Ricci maps in its latest and the beginning of seventeenth century, inspiring again many map projection makers in the twentieth century. In this paper, the revisiting and overview of the oval graticule settings of some representative sixteenth-century maps of this category are followed by studying the relevant metrical and deformational properties, carried out on a family set of these ovals (the ‘Agnese set’ of ovals), involving tools from the cartographic strain analysis. The results give some further insights on this important category of maps, typical of a period in cartography marked by the transition from the Ptolemaean standards to the post- and meta-Ptolemaean era of map representations.

Correlation of Strain Representations of the Potential Anomalies with the Geoid

Geoidal representation of the potential anomalies reflects the anomalous density distribution in the Earth’s interior. An alternative representation of potential anomalies can be done in terms of strain analysis, by comparing the metric tensor of the potential surface bounding a model Earth, with constant internal density, with the metric tensor of the counterpart surface which bounds a model Earth with anomalous internal density distribution. Maps representing strain, induced by the potential anomalies, could be source for very helpful phenomenological information in studying the geodynamical behaviour of the Earth either in global or in regional scale. In this paper, the strain field decomposed into dilatational (isotropic strain) and maximum shear (anisotropic strain) part is compared with the geoidal representation of the potential anomalies. It is shown the high degree of correlation between the dilatational isotropic strain field and the geoid and the poor correlation between the maximum shear anisotropic field and the geoid in the short wavelengths which means that the geoidal representation of the anomalous potential is almost exclusively of dilatational isotropic character.