More recently introduced terms such as 'annually laminated' are synonymous with varve. Of the many rhythmites in the geological record, varves are one of the most important and illuminating in studies of past climate change. Varves are amongst the smallest-scale events recognised in stratigraphy.
PCs are designed to shut down automatically when heat endangers the hardware. To find out if this is your problem, download and install Speedfan. It's small and free. Although Speedfan's basic job is controlling the speed of your PC's fans (you probably guessed that by the name), it also provides the CPU temperature.
That is, since the computer's information is stored in RAM, the PC will resume much quicker than if it were in hibernation or full shutdown mode â just like with standard sleep. The problem is, in the event of a power outage, this information would be lost so any unsaved work may be unrecoverable.