The crochet rib stitches are fighting each other to get away from each other when new ones form at the peaks of the chevron. Creating a rippling outward effect. In every way, the chevron forces the rib stitch to create parting ways, trying to separate. 
 
You have rib stitch sprays, and with this yarn, it’s pretty magical. A crochet diagram is available with this download. 
 
Bernat Blanket Patchwork (300g / 10.5 oz, 201 m / 220 yds)
A -Teal Dreams - 6 Balls
 
Bernat Blanket (300g / 10.5 oz, 201 m / 220 yds)
B - Bright Sage - 1 Ball. Size shown, this ball will get very close to the end if you are not following a gauge. You may need to stop after a 3rd round or get a second ball to complete the 4th round. You will end up with about 20 feet left on the ball. 
 
Hook: 8 mm / L/11
 
Size: 60” wide x 68” long
 
Gauge: 10 sc and 8 rows = 4” [10 cm]