Explaining the Importance of the Geothermal Gradient Calculation: What It Does, and What It Can Do?

With the current dependence for traditional energy source, and the attendant repercussions including global warming more and more governments and private institutions are looking for ways on how to find other alternative sources of energy.

A good portion of the current researches on alternative energies right now focus on the promise of geothermal energy. It has been found out that geothermal energy, if properly utilized from the ground up can become a viable energy and electricity source for mainstream consumers. And this entails understanding the inner workings of the earth’s core and understanding important concepts like the geothermal gradient calculation. Here’s a simple take on the geothermal gradient definition. This is simply the rate of the change of temperature (T) with depth (Z) in the earth.

The gradient temperature can be measured using F/100 feet or C/kilometer. In the computation of the geothermal gradient, keep in mind that the change in temperature is affected by the heat flow which is symbolized by Q.

Heat flow can be calculated using Q=KT/Z where K stands for the thermal conductivity of the rock. The temperature on the other hand varies depending on the depth in the earth’s core. But if you are talking about the temperatures at the surface of the earth, then the temperature is influenced by the heat of the sun and atmosphere. There are instances and areas where the temperature of the surface will be influenced by the hot springs and the lava flows.

Listed below are the temperatures as measured in varying depths of the earth’s core. To shallow depths of 200 feet below the surface, the temperature is measured at 11 Celsius. In that area in between the surface and 400 feet, the gradient will vary and this is influenced by changes in the atmosphere and how strong the groundwater circulates and moves. By further going down, the temperature will increase as the depth increases as well. And this is your geothermal gradient calculation at work.

Also, the geothermal gradient calculation can also change dependent on the area where the calculation is made. For example, you can expect different calculations for the Mid Atlantic Rift and the Aleutian Chain and these are normally known as high gradients. These are usually plotted with the use of a geothermal gradient map, and this map proves helpful for those industries and institutions wanting to take advantage of geothermal gradient.

This map locates not just areas with high gradient (reaching 200 Celsius/km) but this map also list areas or locations that have low gradient (15-30 Celsius/km). So what does it means to know the gradient calculation? This is important in energy exploration and generation. Exploration and energy companies must have knowledge of the geothermal gradient, so that they will know the right set of digging tools to use at a certain area.

If the gradient map suggests that the area is known for high gradient, say the Basin and Range regions in the America and the East Africa’ Great Rift Valley then these areas can serve as the perfect area where the energy generation through geothermal energy can be performed. Energy firms may want to get the geothermal gradient equation, compute for actual gradient and use the result in the design of the tools that can be used to drill and extract the heat which can be pumped through the hot rock.