X0303 4 2011-03-25 0 0001311486 Global Geophysical Services Inc GGS 0001480712 Howell Jeff M 13927 S. GESSNER RD. MISSOURI CITY TX 77489 0 1 0 0 VP, HSEQ Common Stock 149014 D Common Stock 2011-03-25 4 S 0 5000 14.83 D 144014 D The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions during the day at prices ranging from $14.80 to $14.88, inclusive. The reporting person undertakes to provide to the SEC staff, GGS, and any security holder of GGS, full information regarding the number of shares purchased at each separate price within the range set forth above. /s/ Jeff M. Howell 2011-03-28