Explained: How much water is in Earth's crust

Earth's hidden water reserves surpass those in ice caps and glaciers. Groundwater, stored in soil and rock pores, constitutes a significant portion of Earth's water inventory. A 2021 study revealed approximately 43.9 million cubic kilometers of water in the crust, exceeding ice reserves. This underground water, crucial for ecosystems and human needs, underscores the importance of understanding and managing groundwater resources for sustainability in the face of global water challenges. (Image:Unsplash)

The 2021 study in the journal Geophysical Research Letters revealed that Earth's crust holds a substantial amount of water, with groundwater surpassing the volume of water in ice caps and glaciers.(Image:Unsplash)

Grant Ferguson, lead author of the study, stated that approximately 43.9 million cubic kilometers (10.5 million cubic miles) of water reside in the Earth's crust, making it a significant reservoir of water.(Image:Unsplash)

While ice in Antarctica, Greenland, and glaciers outside these regions holds considerable amounts of water, groundwater in the Earth's crust exceeds these figures, according to the study. (Image:Unsplash)

Despite the abundance of groundwater, Earth's oceans remain the largest reservoir of water, holding about 312 million cubic miles (1.3 billion cubic km), as highlighted in the 2021 study.(Image:Unsplash)

The 2021 study expanded previous estimates of groundwater, considering both shallow and deep groundwater within the Earth's crust, including sedimentary rocks, which are more porous than crystalline rocks. (Image:Unsplash)

Ferguson and colleagues more than doubled previous estimates of groundwater from about 2 million cubic miles (8.5 million cubic km) to 4.9 million cubic miles (20.3 million cubic km) within the depth range of 1.2 to 6.2 miles beneath Earth's surface.(Image:Unsplash)

While Earth's crust is typically 19 to 31 miles thick, the study focused on the upper crust (up to 6.2 miles deep), which is relatively brittle and holds fractured rock capable of retaining water.

Deep groundwater, trapped for extended periods, presents an intriguing area for scientific exploration, offering insights into Earth's past and potentially hosting ancient microbial ecosystems.(Image:Unsplash)

Studying deep groundwater ecosystems provides valuable information about the evolution of life on Earth and the potential for life on other planets with subsurface water reservoirs. (Image:Unsplash)