A revised surface age for the North Polar Layered Deposits of Mars. Issue 7 (5th April 2016)

• Record Type: Journal Article
• Authors: Landis, Margaret E.; Byrne, Shane; Daubar, Ingrid J.; Herkenhoff, Kenneth E.; Dundas, Colin M.
• Is Part Of: Geophysical research letters. Volume 43:Issue 7(2016)
• Page Start: 3060
• Page End: 3068
• Publication Date: 2016-04-05
• Subjects: North Polar Layered Deposits, Mars -- impact craters -- spacecraft observations -- impact crater statistics -- Mars polar science; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL068434
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: The North Polar Layered Deposits (NPLD) of Mars contain a complex stratigraphy that has been suggested to retain a record of past eccentricity‐ and obliquity‐forced climate changes. The surface accumulation rate in the current climate can be constrained by the crater retention age. We scale NPLD crater diameters to account for icy target strength and compare surface age using a new production function for recent small impacts on Mars to the previously used model of Hartmann (2005). Our results indicate that ice is accumulating in these craters several times faster than previously thought, with a 100 m diameter crater being completely infilled within centuries. Craters appear to have a diameter‐dependent lifetime, but the data also permit a complete resurfacing of the NPLD at ~1.5 ka. Key Points: Using a new crater production function for current Mars, the NPLD surface age is closer to ~1.5 kyr Accounting for ice target strength suggests that crater model ages are overestimates The north polar deposit on Mars is being resurfaced faster than previously calculated