Preface

Every volcano is considered a peculiar system governed by the law of chaos. The older an active volcano is, the more difficult it is to forecast its behaviour. The only way to characterize a volcano is to collect as much data about it as possible. All physical and chemical data must be collected in order to understand how a volcano works. In a case where a volcano has been deeply studied and much of its behaviour is known (i.e., Somma-Vesuvius volcanic complex), there are several isotope techniques, together with petrology and geophysical data, that can help us to understand when a volcano may erupt. This prediction can only be made when a volcano is well known from the volcanic stratigraphy, volcanological (eruptive mechanism, volume, and other physical parameters), petrographic, petrological, and geochemical points of view (i.e., fumaroles studies of temperature, volatile content, isotopes). Volcanic seismology is a branch of geophysics that considers tremors and volcanic earthquakes to forecast volcanic eruptions. A Synthetic Aperture Radar (SAR)-based survey of volcanic deformation must be taken into serious consideration. This book is a collection of studies on volcanoes all over the world.

Section 1: "Introduction"

This section contains one chapter that summarizes the main concept of Volcanology with an overview that will help to understand other chapters presented in the book.

Section 2: "Applied Volcanology"

In Chapter 2, Borgia et al. present a geothermal study of the power plants of Mount Amiata in Italy. The authors evaluate the lava mound's impact on freshwater aquifers, seismicity, and air. They state that geothermal tools used at Mount Amiata would increase the amount of reinjection, increasing the risk of induced seismicity, and conclude that the use of deep borehole heat exchangers could perhaps be the only viable solution to the current geothermal energy environmental impacts.

In Chapter 3, Iqbal et al. conduct a study in West Lampung, Sumatra, Indonesia, where tropical volcanic residual soils are formed from weathering of volcanic breccias in hydrothermal alteration areas with a thickness of up to 20 m. The volcanic residual soil was studied from a clay mineralogical approach and will be suitable for agriculture purposes, building foundations, and earth construction.

In Chapter 4, Paripurno Eko Teguh introduces a contingency plan that was carried out for the seven highest villages in Sleman Regency, Yogyakarta Special Region, as areas prone to an eruption of Merapi Volcano. This participatory and child-friendly contingency plan is a model for an emergency response to volcanic eruptions during the COVID-19 pandemic. This document may be adapted for other comparable natural disaster contingency plans. This plan will be easy to implement once it is completed with the Operational Plan document.

Section 3: "Volcanic Sedimentology, Geochemistry and Petrology"

In Chapter 5, Ayalew et al. report field observation, textural description, and mineral chemistry for rhyolitic obsidian lavas from previously under-described effusive Badi volcano, central Afar within the Ethiopian rift. The scarcity of explosive products is explained by the fact that the Badi rhyolite domes and flows resulted from initially volatile-poor silicic magma. The Badi lavas flowed outward due to their high magma temperature and peralkaline affinity with increased fluidity.

In Chapter 6, Lagos and Combina state that during the Miocene, in the distal sectors of the Bermejo Basin, a complex relationship developed between a floodplain and contemporary volcanic activity. Seven stages of sedimentation are established to interpret this relationship. The volcanism that generated these deposits is probably associated with the migration to the east of the Miocene volcanic arc of the Cordillera de Los Andes.

In Chapter 7, Bernard and Alexander present a hydrogeochemistry study where the chemical element sources of the Pidong Crater Lake (Panyam Volcanic Province, Nigeria) are derived mainly from water-rock interaction processes. The lake water is mainly Mg–HCO3 water type. The lake water type is meteoric in origin and is relatively young with an age of 230 ± 30 years before the present. Pidong Crater Lake colour change activities are characterized by a decrease in pH. Increases in PCO2 are attributed to intermittent degassing of CO2 gases from fumarole activities from mantle sources.

In Chapter 8, Kumar and Sharma report on the field, petrographical, and geochemical observations of the volcano-plutonic rocks of the Nakora Ring Complex (NRC) from the Neoproterozoic, Malani Igneous Suite (MIS) (Northwestern Peninsular India). The research proposes that the Neoproterozoic magmatism at NRC was controlled by rift-related mechanisms and produced from a crustal source where the heat was supplied by a mantle plume.

Finally, in Chapter 9, Mohammadiha Homayoon presents a petrologic jumble on the origin of anorthosites, which are useful for providing information about the earth's history and evolution. Studying anorthosites yields good information about the conditions of igneous rock formation.

> **Angelo Paone and Sung-Hyo Yun** Pusan National University, Busan, Republic of Korea

Section 1 Introduction
