MétaCan
Menu
Back to cohort
Record W1970494787 · doi:10.1029/1999je001197

Convection in a catastrophic flood deposit as the mechanism for the giant polygons on Mars

2000· article· en· W1970494787 on OpenAlexaboutno aff
M. D. Lane, P. R. Christensen

Bibliographic record

VenueJournal of Geophysical Research Atmospheres · 2000
Typearticle
Languageen
FieldPhysics and Astronomy
TopicPlanetary Science and Exploration
Canadian institutionsnot available
FundersNational Aeronautics and Space Administration
KeywordsGeologyPermafrostConvectionMars Exploration ProgramSubsurface flowMartianGeophysicsConvection cellGeomorphologySedimentary rockLithosphereNatural convectionGeochemistryMechanicsGeotechnical engineeringAstrobiologyGroundwaterTectonicsCombined forced and natural convectionPaleontology

Abstract

fetched live from OpenAlex

A formational mechanism for the large‐scale polygons that are defined by intersecting fractures in the northern plains of Mars is proposed in this work. The presented model is based on Rayleigh convection of interstitial water driven by an unstable density/temperature gradient within a saturated, porous medium. Catastrophic emplacement of water‐rich sediments into the Martian northern plain basins could have provided a thick sedimentary layer in which Rayleigh convection could have occurred. Convection within this active layer is proposed to have differentially thawed an underlying ice‐rich permafrost layer that had been at the planet's surface before being rapidly buried. The resulting morphology of the permafrost subsurface is thought to have resembled the scalloped solid‐liquid interface morphology produced in terrestrial convective flow visualization studies. The exact size and shape of the scallops on the frozen subsurface would have been controlled by the dimensions of the convection cells, which are estimated to have had width‐to‐depth ratios of between 3.4 and 4.5. Subsequent stresses (e.g., gravity and bending stresses) would have produced maximum tensile stresses in the overlying sediments preferentially above the subsurface topographic highs as described previously by McGill and Hills [1992]. Additional desiccation of the sediments would have required contraction of the sediment cover and would have produced large‐scale polygonal fractures along the preexisting weaknesses located above the raised subsurface topography. Thus the underlying subsurface geometric morphology would have been translated to the surface and would be represented by the large‐scale polygonal fractures visible in the Viking Orbiter and Mars Global Surveyor images of the Martian northern plains.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.662
Threshold uncertainty score0.364

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.027
GPT teacher head0.300
Teacher spread0.273 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designTheoretical or conceptual
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations30
Published2000
Admission routes1
Has abstractyes

Explore more

Same venueJournal of Geophysical Research AtmospheresSame topicPlanetary Science and ExplorationFrench-language works237,207