On the global monodromy of a Lefschetz fibration arising from the Fermat   surface of degree 4
  A complete description of the global monodromy of a Lefschetz fibration arising from the Fermat surface of degree 4 is given. As a by-product we get a positive relation among right hand Dehn twists in the mapping class group of a closed orientable surface of genus 3. 
Yusuke Kuno