Water is the Earth's most precious resource. Until recent years, water was often overlooked as being overly abundant or available, but much has changed all over the world. As climate change, human encroachment on environmental areas, and deforestation become greater dangers, the study of groundwater has become more important than ever and is growing as one of the most important areas of science for the future of life on Earth. This three-volume set is the most comprehensive and up-to-date treatment of hydrogeochemistry that is available. The first volume lays the foundation of the composition, chemistry, and testing of groundwater, while volume two covers practical applications such as mass transfer and transport. Volume three, which completes the set, is an advanced study of the environmental analysis of groundwater and its implications for the future. This third volume focuses more deeply on the analysis of groundwater and the practical applications of these analyses, which are valuable to engineers and scientists in environmental science, groundwater remediation, petroleum engineering, geology, and hydrology. Whether as a textbook or a reference work, this volume is a must-have for any library on hydrogeochemistry.
Viatcheslav V. Tikhomirov, PhD, is a professor, engineer, and researcher in the science of groundwater and its practical applications. An associate professor in the Department of Hydrology at the St. Petersburg State University in Russia, he has taught hydrogeochemistry for many years and has over 150 publications to his credit.
The amount of moisture on Earth and its isotopic composition support a suggestion that our water emerged in the process of the formation of the Earth as a planet at the earliest stages of the Solar System evolution. According to the accretion theory, the major source of moisture on Earth could have been cosmic material from two possible basic sources: asteroids and comets, 70-80% of whose volume is water. However, the first measurements showed that in carbonaceous chondrites the D/H isotope ratio is equal to (1.4 ± 0.1) × 10-4 and in six comets from the Oort's cloud it is (2.96 ± 0.25) × 10-4 (Figure 1.1) (Pinti, 2005; Van Kranendonk, 2012). The closeness of the former value to the D/H ratio in the ocean (1.558 ± 0.001) × 10-4 suggests that 90% of moisture volume on Earth had come from the asteroid belt positioned between the orbits of Mars and Jupiter, and only 10%, from comets. In 2011, the entire game had been upset by the isotopic composition of moisture in a comet from the Jupiter family, 103P/Hartley 2 (Hartogh et al., 2011). The D/H moisture ratio value for this comet was found to be equal to (1.61 ± 0.24) × 10-4, i.e., close to the ocean value. This discovery substantially broadened the range of the outer space material capable of having served the source of moisture on Earth and now includes the belt of comets positioned directly beyond the planet Neptune (30-50 a.u.). These data satisfy the requirements of those models of the forming of the early Solar System, which accept higher D/H ratio in comets of the Kuiper Belt than in the Oort Cloud (the former emerged in a colder area of the Solar System than the latter). Moreover, in 2015 the isotopic composition was studied of moisture from Churyumov-Gerasimenko comet (Altwegg et al., 2015) in the same Jupiter family. The moisture's D/H ratio value for this comet had been found to be equal to (5.3 ± 0.7) × 10-4, i.e., the triple value of the Earth's ocean. These data indicate that not all comets in the Jupiter family have moisture contents as in the ocean.
Figure 1.1 D/H ratio of the present-day ocean a = 155.7 × 10-6 (dDSMOW = 0%) (Pinti, 2005).
Whereas during the entire time of Earth's existence the oxygen isotopic composition may have remained unchanged, hydrogen, which more easily loses its lighter isotope, protium, to the outer space may get notably isotopically heavier. The study of oxygen and hydrogen isotopic composition in Isua serpentine of West Greenland in 2012 (Pope et al., 2012) showed that hydrogen in the Archaean ocean water could have indeed been isotopically lighter than in the present-day ocean almost by 25 ± 5%. Lydia Hallis et al. (2015) from the University of Glasgow also attempted to find moisture of the primeval ocean, which would maintain its original isotopic composition. They believe that they found it in the inclusions of ancient lavas on Baffin Island (Canada), where hydrogen isotopic composition was also notably lighter than in the present-day ocean. In this connection, Hallis et al. proposed a hypothesis that Earth moisture was originally notably lighter than in the present-day ocean and that water had come on Earth directly from the proto-Solar gas and dust nebula, which had formed the Solar System.
Water volume on Earth during the period of its existence could have been notably changing. As major water sources, both the outer space and the subsurface are considered. Moisture from the outer space is coming as a component of the cosmic matter. Approximate estimates (Frank et al., 1986) show that only from numerous smaller comets during the period of Earth's existence could have come up to (2.2÷8.5) × 1021 kg of moisture, which is triple the volume of the present-day ocean. On the other hand, Earth subsurface in the process of matter differentiation by the density gradually loses its most volatile components, among them H2O. These volatile components come to the planet's surface in the process of volcanic activity and with numerous hydrotherms. Currently, most experts tend to believe that changes in the natural water volume on Earth were mostly associated with degassing of the subsurface, which had begun immediately after the accretion and continued for the entire duration of its history (de Ronde et al., 1994; Kitajima et al., 2001) through volcanoes and hydrotherms.
The atmosphere is a gas shell, which includes about 12.9 thous. km3 of moisture (Table 1.1). The hydrosphere includes natural water on Earth's surface. Its volume is around 1,338 million km3, which is 96.5% of the identified moisture volume on the planet. Beside liquid water, there is on the surface 24 million km3 of moisture as Arctic and Antarctic ice mountain glaciers. The volume of known ground water is only around 37 million km3, which is around 2.5% of identified water volume. However, a discovery in 2014 by the group of Graham Pearson (Pearson et al., 2014) may notably affect our ideas of the water amount in the planet's subsurface. The theoretical mineralogy and seismic data suggested for a long time (Jacobsen et al., 2008, 2010; Schmandt et al., 2014) that the major component of the transition zone between Earth's upper and lower mantle at depths of 410-660 kilometers must be ringwoodite (Mg, Fe2+)2(SiO4), a mineral belonging to the olivine group. However, this mineral was encountered only in meteorites until D. J. Pearson et al. discovered its inclusions, 40 µm in size, within a diamond from Brazil weighing 0.09 g. This discovery confirms that the transition zone between the upper and lower mantle may indeed be composed of ringwoodite. Analyses indicate that up to 1.5% by weight of this mineral is OH- ion, which means that at the boundary between the upper and lower mantle may exist tremendous amounts (up to 1.4·1021 kg) of chemically bonded moisture.
Table 1.1 Water amounts on Earth (World water resources ., 2003; Gleick, P. H., 1996). Water Covered area, thous. km2 Water volume, thous. km3 Water stratum, m Fraction of total amount, % Fresh water fraction of total amount, %
Atmosphere 510,000 12.9 0.025 0.001 0.04 Oceanic 361,841*
3,700 96.5 0.0 River 148,800 2.12 0.014 0.0002 0.006 Lake 2,058.7 176.4 85.7 0.013 - Fresh 1,236.4 91.0 73.6 0.007 0.26 Salty 822.3 85.4 103.8 0.006 - Biologic 510,000 1.12 0.002 0.0001 0.003 Glacier 16,227.5 24,064.1 1,463 1.74 68.7 Permafrost 21,000 300 14 0.022 0.86 Swamp, fresh 2,682.6 11.5 4.28 0.0008 0.03 Soil 82,000 16.5 0.2 0.001 0.05 Ground water 134,800 23,400 173.5 1.69 - Fresh 134,800 10,530 78.1 0.76 30.1 Salty 134,800 12,870 95.5 0.93 - Total: 510,000 1,386,000 2,718 100 - Total fresh water: 148,800 35,029.2 235 2.53 100
*Current data after Charette et al., 2010.
There are boundaries to natural water distribution on Earth as liquid water solution. The upper boundary is apparently the altitude of cloud distribution in the atmosphere, i.e., around 13 km over the Earth's surface. In clouds, water forms...