Wood drying can/will split naturally
Wood drying too quickly will definitely split
Wood drying on a radiator will definitely split
Wood dries 'naturally' about an inch or so thickness a year
and to top it off...
wood, even when it is dry it can still split when you remove some of the wood as you are releasing the fibres that hold it all together.
Search for 'seasoning' wood - general rule is seal freshly cut log ends immediately and store sensibly, go back a year or two later, or turn to rough shape, leave about an inch even thickness, wrap and store and go back in a year. or turn it green and enjoy natures distortions.