( ( ( ( Frost action ) , ) ( sometimes ( known ( as ( ( ( ( ( ( ( ice ( crystal growth ) ) , ) ( ice wedging ) ) , ) ( frost wedging ) ) or ) freeze-thaw ) ) ) ) ) ( ( occurs ( when ( ( water ( in ( ( ( cracks and ) joints ) ( of rocks ) ) ) ) ( ( freeze and ) expand ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Frost) (NN action)) (, ,) (VP (ADVP (RB sometimes)) (VBN known) (PP (IN as) (NP (NP (NN ice) (NN crystal) (NN growth)) (, ,) (NP (NN ice) (NN wedging)) (, ,) (NP (JJ frost) (NN wedging)) (CC or) (NP (NN freeze-thaw)))))) (VP (VBZ occurs) (SBAR (WHADVP (WRB when)) (S (NP (NP (NN water)) (PP (IN in) (NP (NP (NNS cracks) (CC and) (NNS joints)) (PP (IN of) (NP (NNS rocks)))))) (VP (VB freeze) (CC and) (VB expand))))) (. .)))
Frost action, sometimes known as ice crystal growth, ice wedging, frost wedging or freeze-thaw occurs when water in cracks and joints of rocks freeze and expand.
(ROOT (S (NP (NN Ice) (NN wedging)) (VP (VBZ occurs) (SBAR (IN because) (S (NP (NN water)) (VP (VBZ expands))))) (. .)))