Introduction to this special section: Near-surface geophysics

The near surface of the earth, a.k.a. the critical zone (National Research Council, 2001), is defined as the outer 50-100 m of the planet, which contains biota, bedrock, soil, water, and gasses. As humans, we rely on this layer for many functions including storage of water resources, housing of our infrastructure, storage of our wastes, and cultivation of our food sources. Several natural ecosystems are also dependent on this layer of our planet, which in turn provide us with ecosystem services. The historic and lasting importance of this layer to our environment emphasizes the value in understanding major environmental fluxes, impact of human activities, and the interface between the natural world and our infrastructure. Application of geophysical methods in this field has increased steadily over the past 15 years and continues to grow, especially as the human impact on the globe continues to increase. © 2019 by The Society of Exploration Geophysicists.