Current Status and Forecast. n Tropical Pacific sea-surface temperatures (SSTs) have warmed from La NiÃ±a. Modoki (below-average SSTs, centered in the central tropical Pacific) to ENSO-neutral. Current SSTs range from slightly below average in the central Pacific to slightly above. average in the eastern Pacific. n The Climate Prediction Center (CPC) defines a La NiÃ±a event as having ONI values. of -0.5Â°C or colder for 5 consecutive months.
Convection currents move tectonic plates when there is heat inside the mantle that is rising and falling. The radioactive decay in the core is responsible for the convection currents.
The Earthâs crust and upper part of the mantle is broken into large pieces of rock. These large pieces of rocks are called tectonic plates. Tectonic plates never stop moving, this process is called continental drift. Tectonic plates move because of convection currents. These convection currents happen in the mantle, underneath the tectonic plates. The heat, which causes the convection currents, is produced from the radioactive decay left over from the Earths formation.