Abstract
The cavi unit at the north pole of Mars is a deposit of aeolian sand and water ice underlying the Late Amazonian north polar layered deposits. Its strata of Middle to Late Amazonian age record wind patterns and past climate. The Mars Reconnaissance Orbiter Shallow Radar (SHARAD) reveals extensive internal and basal layering within the cavi unit, allowing us to determine its general structure and relative permittivity. Assuming a basalt composition for the sand (ε′ = 8.8), results indicate that cavi contains an average ice fraction between 62% in Olympia Planum and 88% in its northern reaches beneath the north polar layered deposits and thus represents one of the largest water reservoirs on the planet. Internal reflectors indicate vertical variability in composition, likely in the form of alternating ice and sand layers. The ice layers may be remnants of former polar caps and thus represent a unique record of climate cycles predating the north polar layered deposits.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 7278-7286 |
| Number of pages | 9 |
| Journal | Geophysical Research Letters |
| Volume | 46 |
| Issue number | 13 |
| DOIs | |
| State | Published - Jul 16 2019 |
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Keywords
- Cavi unit
- Climate Record
- Composition
- Mars
- Radar
- Stratigraphy
ASJC Scopus subject areas
- Geophysics
- Earth and Planetary Sciences(all)
Cite this
Buried Ice and Sand Caps at the North Pole of Mars : Revealing a Record of Climate Change in the Cavi Unit With SHARAD. / Nerozzi, S.; Holt, J. W.
In: Geophysical Research Letters, Vol. 46, No. 13, 16.07.2019, p. 7278-7286.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Buried Ice and Sand Caps at the North Pole of Mars
T2 - Revealing a Record of Climate Change in the Cavi Unit With SHARAD
AU - Nerozzi, S.
AU - Holt, J. W.
PY - 2019/7/16
Y1 - 2019/7/16
N2 - The cavi unit at the north pole of Mars is a deposit of aeolian sand and water ice underlying the Late Amazonian north polar layered deposits. Its strata of Middle to Late Amazonian age record wind patterns and past climate. The Mars Reconnaissance Orbiter Shallow Radar (SHARAD) reveals extensive internal and basal layering within the cavi unit, allowing us to determine its general structure and relative permittivity. Assuming a basalt composition for the sand (ε′ = 8.8), results indicate that cavi contains an average ice fraction between 62% in Olympia Planum and 88% in its northern reaches beneath the north polar layered deposits and thus represents one of the largest water reservoirs on the planet. Internal reflectors indicate vertical variability in composition, likely in the form of alternating ice and sand layers. The ice layers may be remnants of former polar caps and thus represent a unique record of climate cycles predating the north polar layered deposits.
AB - The cavi unit at the north pole of Mars is a deposit of aeolian sand and water ice underlying the Late Amazonian north polar layered deposits. Its strata of Middle to Late Amazonian age record wind patterns and past climate. The Mars Reconnaissance Orbiter Shallow Radar (SHARAD) reveals extensive internal and basal layering within the cavi unit, allowing us to determine its general structure and relative permittivity. Assuming a basalt composition for the sand (ε′ = 8.8), results indicate that cavi contains an average ice fraction between 62% in Olympia Planum and 88% in its northern reaches beneath the north polar layered deposits and thus represents one of the largest water reservoirs on the planet. Internal reflectors indicate vertical variability in composition, likely in the form of alternating ice and sand layers. The ice layers may be remnants of former polar caps and thus represent a unique record of climate cycles predating the north polar layered deposits.
KW - Cavi unit
KW - Climate Record
KW - Composition
KW - Mars
KW - Radar
KW - Stratigraphy
UR - http://www.scopus.com/inward/record.url?scp=85068793279&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85068793279&partnerID=8YFLogxK
U2 - 10.1029/2019GL082114
DO - 10.1029/2019GL082114
M3 - Article
AN - SCOPUS:85068793279
VL - 46
SP - 7278
EP - 7286
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 13
ER -