Frost heave/ frost beard/ Needle Ice 14/52 WTFND
In the spring as the ground warms up the frost in the ground heaves itself up pushing whatever is in it's way up. These fine shafts of frost are abut 2 inches long and have pushed their way up through the gravel on the road.
Needle Ice as defined in Wikepedia:
Needle ice is a phenomenon that occurs when the temperature of the soil is above 0 °C (32 °F) and the surface temperature of the air is below 0 °C (32 °F). The subterranean liquid water is brought to the surface via capillary action, where it freezes and contributes to a growing needle-like ice column.
The ice needles are typically a few centimetres long. While growing, they may lift or push away small soil particles. On sloped surfaces, needle ice may be a factor contributing to soil creep.