Slope Dependent Morphometric Analysis as a Tool Contributing to Reconstruction of Volcano Evolution

Abstract

IntroductionPeople have been fascinated by volcanoes since time immemorial. This is mainly due to the serious consequences that volcanic eruptions represent for human society. Volcanic activity develops in various ways. Therefore, evolutionary trends and the history of the volcanic system should be well understood when future hazards must be predicted and their impact on human society reduced. A volcano's history can be reconstructed from its deposits, their superposition and spatial relationships. Geological mapping is the crucial method for acquiring this information. Unfortunately, large areas in volcanic zones are inaccessible for research directly in the field. In these areas, the geological setting must be investigated by a combination of remote sensing methods and field observations from accessible outcrops. Surface methods such as remote sensing and morphological analysis provide fast and relatively cheap information, complementary to classical field geology for studying the subsurface geology. These methods can be beneficial, especially for areas with poor accessibility and/or dense vegetation cover. Volcanoes or volcanic complexes quite often represent such areas. Land forms are a result of geologic and geomorphologic processes that occur on the earth's surface thus land forms are not chaotic, but have been structured by geologic and geomorphologic processes over time. The geomorphology of volcanic formations as a whole seems to be a reflection of the underlying geology with steep-sided land forms occurring at each of the "strong" rock units and long, with gentle slopes and topographic breaks found on "soft" rocks. To support this theory, we employed and tested new methodology combining information arising from field surveys together with visual interpretation and statistical spatial analysis of morphometric slope-depending classes to define the spatial extent of various volcanic formations and to identify major tectonic phenomena from features derived from the geomorphology in more accurate way. Study areasMorphometric analysis was applied to two case study areas, two volcanic complexes of distinct geotectonic setting, age and volcanic evolution. Selected volcanic areas encompass a www.intechopen.com Earth and Environmental Sciences 220 number of features and rock types associated with volcanic activity. The first case study was carried out in the Conchagua Volcanic Complex, El Salvador (Central America), while the second one was performed in the Doupovské hory Volcanic Complex, Czech Republic (Central Europe). Conchagua VolcanoThe Pacific coast of Central America is bordered by a chain of active subduction-related volcanoes. This chain is called the Central American Volcanic Arc (CAVA) and extends from Guatemala via El Salvador, southern Honduras, Nicaragua and Costa Rica to western Panama (e.g., Carr et al., 2003). The volcanic arc is associated with the subduction of the Cocos plate beneath the Caribbean plate and it is divided into several segments by traverse faults. Conchagua Volcano is located ...

Morphometric analysis of the Scoria Cones and drainage pattern for the Quaternary and older Volcanic Fields in parts of the Large Igneous Province (LIP), Saudi Arabia

“…Analogous situations are also known from elsewhere (cf. Kopačková et al, 2011). The drainage texture which refers to the relative spacing between the drainage lines was also determined; this is found to vary from 3.16 to 3.53 for the four volcanic fields, (Table 5).…”

Main Ethiopian Rift landslides formed in contrasting geological settings and climatic conditions

“…rock strength and degree of weathering) so they can be identified by these numerical methods. Various studies have been carried out to link morphometry with fluvial erosion, tectonics and diverse geomorphological conditions, and volcanic activity (Altin and Altin, 2011;Bolongaro-Crevenna et al, 2005;Ganas et al, 2005;Kopačková et al, 2011;Rapprich et al, 2010). Morphometric maps were constructed utilizing Wood's algorithm based on Shuttle Radar Topography Mission (SRTM) DEM data (30 m pixel resolution).…”

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“…To date, acoustic remote sensing techniques are the most popular ones in seabed mapping and classification [3,4]. For instance, [5] asserted that this technology offers an advantage to subsurface geological investigation due to the poor accessibility in study area. Multibeam sonar, which is one of such technologies, can provide a dense and seamless bathymetric Digital Elevation Model.…”

“…Landform and seafloor morphology consists of a complex process such as tectonic evolution and volcano growth. The morphometric analysis offers information to characterize that morphology quantitatively, for example by determining the size and shape of the volcanoes [5,6]. Another instance was shown by [7] who revealed the driving process of a large seamount by analyzing morphometric derivation features.…”