When you look at other blips, the land blips are 1.5 to 2 times (roughly) the ocean blips higher sensitivity plus thermal inertia effects.

WSJ: Climate Emails: Science and Candor

Satellite observations indicate this landscape has a high thermal inertia - that is to say, at night it loses heat more slowly than the terrains that abut it in the local area.

BBC: Mars rover finally looks set to drill