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.
If your computer is plugged into a wall socket that's switched on, even when it's in standby or sleep mode, it's vulnerable. That's because the lightning current can travel through the power cord or any other cable connected to your computer, says Phung. So if you think a storm is coming, you should physically disconnect your computer from the mains socket to protect it from a lightning surge, he says.