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Natural subsurface temperature profile along the True Vertical Direction: $//<![CDATA[ \begin{array}{l}T(z)\end{array} //]]>$, where $//<![CDATA[ \begin{array}{l}z\end{array} //]]>$ is True Vertical Depth Sub-Sea (TVDss).

It is essentially a true vertical component of local Geothermal Temperature Field  $//<![CDATA[ \begin{array}{l}T(x, \, y, \, z)\end{array} //]]>$.

Many subsurface studies are focused on rocks below a specific surface area where lateral ( $//<![CDATA[ \begin{array}{l}\{ x, \, y \}\end{array} //]]>$) variation of Geothermal Temperature Field maybe insignificant comparing to true vertical ( $//<![CDATA[ \begin{array}{l}\{ z\}\end{array} //]]>$) variation.

This allows using Geothermal Temperature Profile  $//<![CDATA[ \begin{array}{l}T(z)\end{array} //]]>$ instead of Geothermal Temperature Field  $//<![CDATA[ \begin{array}{l}T(x, \, y, \, z)\end{array} //]]>$. 

See Also

Geology / Geothermal Temperature Field

[ Petroleum Geology ][ Geological Model (GM) ]

[ Geothermal Temperature Profile @model ]