What is the main cause of guttation in plants?

Guttation is the process of loss of water from the surface of leaves in the form of liquid drops... Guttation occurs when root pressure is high and transpiration is low.

meteorologists would compare a new weather map with one 24 h old to see how fast a front is moving.

that would be called plucking : )

explanation:

''plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the erosion and transportation of individual pieces of bedrock, especially large "joint blocks". as a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock."