What is subsidence?
Subsidence and/or ground movement is an event caused by Nature it is unpredictable and extremely difficult to avoid. The degree of subsidence is dependent on individual site conditions including, but not limited to, weather (prior to, during and after installation), soil type and location of installation. It is an event not covered by warranty. Subsidence around tanks installed in-ground may result in increased pressure on any pipework connected to the tank. Sometimes this increased pressure will result in the pipework/fitting becoming “sheared off”, stretched or split (leaking) or broken. Defects arising from subsidence are not covered by warranty. Generally subsidence only occurs in the first instance of changed weather conditions (ie after rain) however it may occur under other circumstances. Usually after the first instance the ground (and consequently the tank and other componentry) “finds it level” and you should not experience any further problems from this phenomenon. In very r
Subsidence is the slow descent of air from the upper troposphere. As the air descends, heat of compression increases its temperature. Air from near the top of the troposphere has the potential of becoming much warmer than the air at the bottom of the atmosphere when brought down to the surface. Compressing air from 20 kPa to 100 kPa without cooling increases its temperature from -60C to +60C. Without cooling the resulting buoyancy would inhibit subsidence. Infrared radiation to space cools the subsiding air by 1 to 3C per day thereby limiting the temperature increase of the subsiding air. Atmospheric convection is an unsymmetrical process. Air brought up quickly from the bottom to the top of the troposphere can have a temperature close to that of the ambient air at the top of the troposphere. Air brought down quickly from the top of the troposphere would have a much higher temperature than the ambient air at the bottom of the atmosphere. Consequently atmospheric convection consists mai
