phi scale

Related Overviews


More Like This

Show all results sharing these subjects:

  • Environmental Science
  • Earth Sciences and Geography


Show Summary Details

Quick Reference

The expression of grain sizes on a logarithmic scale. The phi value (ϕ) is related to grain diameter (d) by the expression ϕ = -log2d. Increasing positive phi values are for grain diameters progressively finer than 1000 μm, and increasing negative values for grain diameters progressively coarser than 1000 μm (e.g. 2ϕ = 250 μm; 1ϕ = 500 μm; 0ϕ = 1000 μm; -1ϕ = 2 mm; -2ϕ = 4 mm).

Subjects: Environmental Science — Earth Sciences and Geography.

Reference entries

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.