Thicker lags, and/or older troughs, would generate TMPs of constant slope, which does not match the observed paths. Models using nominal values of lag diffusivity, albedo, and atmospheric water vapor abundance and in which the trough walls have been covered in a lag on the order of millimeters thick and formed ~2.3 Myr ago match the observed trough migration and align with expectations of trough ages. We present a phenomenological model that combines our simulations of the sublimation conditions at paleo-trough surfaces with accumulation rates to create synthetic TMPs that are tunable to the observations. We constrain the contribution of insolation-induced sublimation to the migration in the observed TMPs. We investigate two adjacent troughs presently near 87°N to evaluate the mass balance conditions at those sites. Discontinuities in stratigraphy seen by radar highlight Trough Migration Paths (TMPs), which provide a record of the troughs' position, formation, and evolution to the present day.

Sublimation at the trough wall produces a growing sublimation lag that modulates further retreat however, winds move material off the retreating slope faces, thinning the lag. Insolation is suspected to drive ice retreat through sublimation. As the north polar layered deposits accumulate, troughs migrate approximately poleward, anti-parallel to the local wind patterns. it explores themes around communication on multiple levels and urges its audience to pay attention.Mars' iconic polar spiral troughs are 400–1,000-m-deep depressions in the north polar layered deposits. She's facing her own challenges and the fact that these are glimpsed only obliquely, with neither parent able to give her as much attention as she needs, makes her situation all the more poignant.Īn intelligent, socially astute film that invites more privileged viewers to question how much they might be missing in the world around them, Spiral is at its best when exploring the power imbalances in relationships and all the little ways in which people fail to listen to each other. Laporte does a good job of communicating vulnerability without diminishing our sense of her character's agency. There's some interesting work around Kayla's coming of age that feels fresh and different disturbing with the familiar shadow of paternal sexual proprietorship taken out of the equation. Whilst some other aspects of the film feel formulaic, Malik's predicament makes it difficult to draw easy conclusions. His performance really elevates the film and makes it worthy of attention whether or not you ordinarily take an interest in genre work.

Bowyer-Chapman is superb, making us feel for him even when we really can't tell what's real, showing us an intelligent man doing his best to remain rational in a crazy situation. It's complicated by the fact that Malik has had paranoid episodes in the past and can't fully trust his own senses (there is perhaps a subtle comment here about the disproportionate diagnosis of schizophrenia in African-American men). One of those films that just couldn't have been made before cinema made room for gay characters beyond the fringes, Spiral takes the tradition of gaslighting and disbelief to which female characters in dangerous circumstances have been subjected for years and turns it on a man, who is made vulnerable by his race in ways that just don't occur to Aaron. Well, maybe it doesn't look that way to a middle class white man. The world isn't like that anymore, he says. Aaron, who has presumably helped him through PTSD, is quick to dismiss all this. But is this new place safe? Malik quickly picks up on homophobic and racist dogwhistles, and there are less subtle occurrences which make him understandably uncomfortable. A brief opening scene which echoes that of David Fincher's Zodiac hints at an underlying trauma in Malik's past. Life out here in the small town by the lake is supposed to be simpler and easier - better for Kayla, whom they both worry about in the city where it feels like anything could happen. But has their relationship ever really faced much stress? They've been together for a long time now things feel easy between them.

Men are mostly pretty awful really, he says, except for her dad - and Aaron (Ari Cohen) smiles contentedly. She's at an age where hearing about others' mistakes might help her to avoid her own. Sitting in the living room on their first night in their new home, Malik (Jeffrey Bowyer-Chapman) is talking to step-daughter Kayla (Jennifer Laporte) about men.

Spiral 2019