Radargrams acquired over Mars polar caps allow observing clear echoes up to kilometers depth.
In 2009, researchers using a smaller array of seismometers claimed to have found a shallow magma chamber at 2 kilometers' depth.
The Five Islands of south central Louisiana are piercement-type salt domes uplifted from several kilometers depth as the surrounding strata experiences regional subsidence.
A 'top down' approach can be used to calculate temperatures in the subsurface up to several kilometers depth by applying the Fourier equation of heat conduction: q=-lambda cdot frac{dT}{dz} (1) Figure 11 Different temperature zones at the base of the Buntsandstein hydrothermal reservoir.
Magnetotelluric (MT) method is able to investigate the geo-electric structure up to several hundreds of kilometers depth and has proven to be capable in designing hypotheses for fluid-induced tectonic mechanisms (e.g., Ritter et al. 2005; Jiracek et al. 2007; Wannamaker et al. 2009; Unsworth 2010).
"These seismic observations offer a window into the magmatic system and forces acting at several kilometers' depth – arguably the region that's sourcing the magma for these eruptions," study co-author Dr. Eric Dunham, an assistant professor of geophysics at Stanford University, said in a written statement.
Still another scheme for alternative cooling has been in place in Toronto for eight years: a "deep water source cooling" system in which cool water is pumped from a five-kilometer depth in Lake Ontario to participating office buildings and through metal coils.
More extensive ground deformation observed by Geospatial Information Authority of Japan showed a source of increasing pressure at 6 10 km depth, several kilometers northwest of Shinmoedake from the end of 2009 (Imakiire and Oowaki, 2011).
The most common and simple type of a hydrothermal system is a hydrothermal doublet (two-well system), consisting of a reservoir heat exchanger commonly at a depth of several kilometers (<5 to 6 km depth) exploited by a warm/hot production well, a heat exchanger at the surface for transferring the heat to a secondary circuit and a cold injection well.
Outside of the seasonal variations, the geothermal gradient of temperatures through the crust is 25 30 °C (77 86 °F) per kilometer of depth in most of the world.
Because surface waves at these frequencies are sensitive to a few tens of kilometers in depth, ANT has been applied to many regions to study crustal structures (e.g., Shapiro et al. 2005; Moschetti et al. 2007; Lin et al. 2008; Li et al. 2009; Yang et al. 2011; Nicolson et al. 2012).
