[X] My Assistant

[ngunn]

I too have a long term interest in this question, but frustratingly cannot access the full text of Perron et.al. I am trying to find a good detailed map of the putative shorelines (not just a global image). Alex (or anyone) do you have a link to such a map, perhaps from earlier in this long running debate?

On a separate question - I have been wondering whether these oceans retreated due to evaporation from the liquid state or whether, rather, they might have frozen first then sublimed. In the latter case of course vertical warping of the shorelines could have occurred with some of the (frozen) ocean still in place. This would presumably alter the dynamics of the situation and would also create a time gap between when the shorelines formed and the crater-count age of the plains surfaces. Is this scenario discussed anywhere in the literature?

[dvandorn]

There is also a question as to whether shorelines might have been altered due to glaciation effects. Any liquid ocean did probably end its life as a frozen-over body of water, which could have induced glaciation effects, especially around the fringes (which happen to be the shorelines).

We shouldn't necessarily expect that ancient Martian shorelines will resemble ancient Terrestrial analogues.

-the other Doug

[Guest_AlexBlackwell_*]

The initial MGS MOLA data (ca. 1998; published in Geophysical Research Letters) looked promising for Contact 2.

This is the paper I was referring to.

[Guest_AlexBlackwell_*]

I've closely followed Oceanus Borealis in the literature ever since Tim Parker published his first paper...

For those who are interested, below are some (but certainly not all) of the key references in the Oceanus Borealis, Mars issue. I haven't bothered with LPSC or other similar conference presentations.

Transitional morphology in the west Deuteronilus Mensae region of Mars: Implications for modification of the lowland/upland boundary
Parker, T. J., R. S. Saunders, and D. M. Schneeberger,
Icarus 82, 111–145, (1989).

Coastal geomorphology of the Martian northern plains
Parker, T. J., D. S. Gorsline, R. S. Saunders, D. Pieri, and D. M. Schneeberger
J. Geophys. Res. 98, 11,061–11,078, (1993).

Oceans or seas in the Martian northern lowlands: High resolution imaging tests of proposed shorelines
Malin, M. C., and K. S. Edgett,
Geophys. Res. Lett. 26, 3049–3052, (1999).
Reprint (2.9 Mb PDF)

Oceans in the past history of Mars: Tests for their presence using Mars Orbiter Laser Altimeter (MOLA) data
Head, J. W., M. A. Kreslavsky, H. Hiesinger, M. A. Ivanov, S. Pratt, N. Seibert, D. E. Smith, and M. T. Zuber
Geophys. Res. Lett. 25, 4401-4404, (1998).
Abstract

Possible ancient oceans on Mars: Evidence from Mars Orbiter Laser Altimeter data
Head, J. W., H. Hiesinger, M. A. Ivanov, M. A. Kreslavsky, S. Pratt, and B. J. Thomson
Science 286, 2134– 2137, (1999).
Full text
Press release

The evolution of the Martian hydrosphere: Implications for the fate of a primordial ocean and the current state of the northern plains
Clifford, S. M., and Parker, T. J.
Icarus 154: 40-79, (2001).
Abstract

Chryse Planitia, Mars: Topographic configuration, outflow channel continuity and sequence, and tests for hypothesized ancient bodies of water using Mars Orbiter Laser Altimeter (MOLA) data
Ivanov, M. A. and J. W. Head, III
J. Geophys. Res. 106, 3275-3295, (2001).
Reprint (6.5 Mb PDF)

Enigmatic ridges on the plains of Mars
Withers, P. and G.A. Neumann
Nature 410, 652, (2001).
Reprint available (scroll to bottom of page)

Outflow Channels May Make a Case for a Bygone Ocean on Mars
by Linda M. V. Martel
PSRD Release (June 14, 2001)

Oceans on Mars: An assessment of the observational evidence and possible fate
Carr, M. H., and J. W. Head
J. Geophys. Res. 108 (E5), 5042, (2003).
doi:10.1029/2002JE001963
Reprint (2.15 Mb PDF)

Ancient Floodwaters and Seas on Mars
by Linda M. V. Martel
PSRD Release (July 16, 2003)

[stevesliva]

Thank you, Alex. Most especially for the PSR articles.

[ngunn]

Thanks Alex - excellent stuff there.