Faculty of Geosciences
Research group River and delta morphodynamics
Nomenclature used on this poster is approved by the IAU (Juventae Cavi, Hydrae Cavus, Pital Crater and Hydrae Chaos).
Used data Mola gridded elevation data (Zuber et al., 1992), THEMIS day and night IR mosaic (Christensen et al., 2004; Fergason et al., 2013), CTX imagery (Malin et al., 2007), MOC imagery (Malin et al., 1992), HiRISE imagery (McEwen et al., 2007) and HRSC imagery and DEMs (Jaumann et al., 2007; Scholten et al., 2005).
References Christensen et al, 2004, Space Sci. Rev. 110, 85, doi:10.1023/B:SPAC.0000021008.16305.94. Fergason et al, 2013. Lunar Planet. Sci. Conf. XLIV, abstract 1642. Jaumann et al, 2007, Planet. Space Sci. 55, 928, doi:10.1016/j.pss.2006.12.003. Malin et al, 1992, J. Geophys. Res. 97, 7699, doi:10.1029/92JE00340. Malin et al, 2007, J. Geophys. Res. 112, E05S04, doi:10.1029/2006JE002808. Marra et al, 2015, J. Geophys. Res. Planets 119, 2668, doi:10.1002/2014JE004701. McEwen et al, 2007, J. Geophys. Res. 112, E05S02, doi:10.1029/2005JE002605. Scholten et al, 2005, Photogramm. Eng. Remote Sens. 71, 1143, doi:10.14358/PERS.71.10.1143.
Zuber et al, 1992, J. Geophys. Res. 97, 7781, doi:10.1029/92JE00341.
Figure 1: Groundwater outflow morphology, photographs of the scale experiments (Marra et al, 2015). (a) Outflow from seepage above the source area with downstream lobes and incising channel. (b) Outflow pits with standing water surrounded by sedimen- tary lobes, converging flow features and downstream valleys. (c) Radial cracks due to formation of subsurface reservoir moments before outflow. (d) Close-up of source area showing converging flow morphology and terraces in the background. (e) Close-up of outflow pit (lower right and upper right) with sedimentary lobe, incised valley and smaller lobes of initial outflow (upper middle).
(f) Close-up of sieve lobe with later incised valley in the background.
• From a hydrostatic (unpressurized) aquifer, groundwater emerges at
depressions at the surface (Figure 2a).
• Groundwater can become pressurized when confined, e.g. by the cryosphere (Figure 2b).
• Pressure could be driven by a elevation difference between infiltration
source and outflow location.
• Groundwater could become pressurized by local processes like tectonism
and volcanism (Figure 2c).
• Furthermore, subsurface obstructions may produce seepage at the surface (Figure 2d)
Figure 2: Hypothesized groundwater outflow mechanisms for Mars. (a) Groundwater outflow due to seepage from a hydrostatic aquifer, resulting in ponding in a depression and outflow at slopes. (b) In case of a pressurized aquifer, depressions can overflow and outflow locations are a function of subsurface properties. (c) Local pressurization and (d) subsurface heterogeneities may alter the outflow location.
• Lobes indicate infiltration in early stage outflow
• Channelization: sustained outflow • Holes / sand volcanoes: fissure outflow
• Cracks / bulging: high pressure outflow
EXPERIMENT RESULTS: SMALL-SCALE MORPHOLOGY
RECONSTRUCTION OF GROUNDWATER SYSTEM
• Strong relation between outflow locations and tectonic structure:
- Outflow features described here and other outflow channels
- Indicates single, closed aquifer - increasing pressure at surface with same base pressure
• Outflow activity throughout history:
- Hesperian large outflow channels, perhaps still recharged by infiltration - Continued activity in Amazonian
- Post-Valles Marineris activity: sustained pressure or re-pressurized by tectonism
• Climate: no warm conditions required for tectonic-triggered groundwater outflow
GROUNDWATER OUTFLOW PROCESSES
Wouter Marra
Pressurized groundwater systems in Lunae and Ophir Plana (Mars):
insights from small-scale morphology and experiments
WOUTER A. MARRA
1, w.a.marra@uu.nl M.G. KLEINHANS
1, S.M. DE JONG
1, E. HAUBER
21Fac. of Geosciences, Utrecht University, the Netherlands, w.a.marra@uu.nl;
2Institute of Planetary Research - DLR Berlin, Germany;
CONCLUSIONS
• Groundwater outflow creates:
- Lobes (early stage)
- Incised valley (later stage)
- Crack and pits (high pressure source)
• Small outflow features on Mars:
- Lobes (Hydrae Cavus, Ophir Catena) - Channelized lobes (Ganges Catena) - Small outflow channel (Juventae Cavi) - Fractured features without outflow
IMPLICATIONS
• Trend in outflow magnitude in Ophir and Lunae Plana consistent with
pressurized outflow from single aquifer.
• Outflow triggered by tectonics.
• Sustained presence of groundwater for large part of Martian history.
• Climate does not require an optimum.
Martian
v
4
2 5
3
1
0 0 500 1000 Distance (km)
Elevation (km)
Chasmata /
lakes? Small
lobes Channelized
lobes Allegheny
Vallis Elaver
Vallis Maja
Vallis
hydrostatic level 1.2 km
4.5 MPa
1.8 km
6.7 MPa 2.2 km
8.2 MPa 3.0 km
11 MPa
headpressure 0.4 km
1.5 MPa
cryosphere aquifer
fissures
pits
chaotic terrain (fissure and pit width not to scale)
c
d e f
~ 0.5 m ~ 0.5 m ~ 0.5 m
~ 0.5 m ~ 0.5 m ~ 10 cm
a b
Lobe Incision
Ponding
Bulging
Radial cracks
Pits
Sand volcano
Converging flow Incised valley
Lobe
Incised valley Ponding
Pit
Sand volcano Converging flow
Lobe Incised valley
source
source
source source
source
-44°
-46°
0°-2°-4°
40km -3.5 km 1.5 km
-22° d -23°
0°-1°
-60°
-6°
20km
3.5km
-21°
-10°
10km
a
c
b
-3.5 km -750 m
2 km 2.6 km -3 km -1 km
Hydrae Chaos
Ravi Vallis Shalbatana Vallis
-66°
-67°
-3°-4°
IS
IS IS
WR
D WR
WR
Ejecta Crater PitCh
Shallow Pit
Lobe
IS IS
d e
a b c
30 km
5 km
3 km
2.5 km 3.2 km d
e
-69°
-3°
g f
10 km 3.0 km 3.7 km 2 km
g
´
´
´
east Ganges Catena
west G
anges Catena
A' A
-60°
-7°-8° -61°
WR A'
WR
WR
WR
WR F
C
A
Lobe Pit
a b c
20 km 1.6 km 3.2 km
d
e
WR
WR F
F
Lobe
d e
4 km ´ 2 km ´
50 m1 km
0 5 10 15 20
2500 2600
distance (km)
elevation (m)
lobe wr
A
A’
f wr
?
Hydrae Cavus
A'
A
A'
B' C'
D'
A
B C
D -57°
-58°
-59°
-3°-4°
Ridge Ridge
Colla pse
Chaos Crater
Pit
Ejecta Channel
a b c
40 km 800 m 2.2 km
d e
f
d
3 km
e
5 km 45°
50°
d
e
´ ´
A
A’
100 m
2 km
0 5 10 15 20 25
1600 m1800 m
2000 m B B’
distance (km) 1200 m1400 m1600 m 0 5 10 15 20 25 30
C
C’
distance (km)
D D’
100 m
2 km 50 m
2 km faults
faults
chaos
channel
channel
f g
Juventae Cavi
Chaotic Terrain
Outflow Channel
-61°
-62°
-63°
-9°-10°
fault craterImp.
L1
L1 L2
Ejecta Catena
L2 d
a b c
50km
7km 2 km 4.5 km
e d
e
4 km N110°
N105°
´ ´
Ophir Catena Pital
overflow fissure outflow
b) Pressurized confined aquifer d) Subsurface heterogeneities
obstruction seepage
fissure outflow
ponding seepage
a) Hydrostatic aquifer c) Local pressurization of aquifer
Legend
pressure head
local pressurization
aquifer cryosphere regolith
water dyke
-50°
-60°
-70°
0°-10°
-60°
-65°
-5°-10°
Juventae Chasma Hydrae
Chasma
Hydrae Cavus
Ganges Cavus Juventae
Cavi
Hydrae Chaos
O P H I R P L AN U M L U N A E P LA N U M
VALLES M
ARINERIS
Ophir Cavus Catena
Ophir Chasma
Ophir Catenae Ganges-
Melas Chasma
Candor Chasma
Coprates Chasma
Ganges Chasma
Coprates Catena
E laver Vallis Allegheny
Vallis
Maja
Valles
Juventae Chasma
Hydrae Chasma
Hydrae Cavus
Juventae Cavi
Hydrae Chaos
Pital Crater Catena
Ophir Catenae Ganges-
Candor Chasma Figure 4
Figure 5a Figure 5f
Figure 6
Figure 7
Figure 8c
´
a b
100km - 4 km 5 km
200km 1 km 2 km 3 km
INTRODUCTION
Outflow channels on Mars are related to the re- lease of groundwater from pressurized aquifers.
However, the hydrological and corresponding cli- mate conditions remain a subject of debate and many more small features show important details.
METHODS
We investigate the detailed morphology of possible pressurized groundwater outflow systems in com- parison to landscape evolution experiments.
• Experimental setup consists of a flume of 6 m long x 4 m wide and 1.20 m
deep. See Marra et al., 2015.
Comparison of Martian morphology using image- ry and elevation data.
MARS: OPHIR AND LUNAE PLANA - BETWEEN THE OUTFLOW CHANNELS
HYDRAE CAVUS: LOBE FROM PIT
• Pit formed by collapse
• Lobe represent early stage outflow
Figure 4: Morphology of Hydrae Cavus.
Figure 3: Overview map of study area. (a) Colored MOLA data overlain by daytime THEMIS IR mosaic with 1, 2, and 3 km MOLA-contours. (b) Daytime THEMIS IR mosaic showing extends of mapped area in Figures 4-7
GANGES CATENA: CHANNELIZED LOBES
• Pit chain relates to tectonic structure
• Lobe represent early stage outflow
• Channalization due to sustained discharge
Figure 5: Outflow features from Ganges Catena.
JUVENTAE CAVI: COLLAPSE AND OUTFLOW
• Field of pits: collapse related to Chasmata
• Chaos and outflow channel: high energy outflow
Figure 6: Juventae Cavi and associated outflow channel.
OPHIR CATENE: LOBES FROM PIT CHAIN
• Pit chain relates to tectonic structure
• Lobe represent early stage outflow
• Lobe age: Amazonian, 1.23 Ga
Figure 7: Lobes around Ophir Catena.
Figure 8: Several fractured features possibly related to pre-outflow processes. a) Floor-fractured crater, b) Fractured rise in Margaritifer Chaos, c) Hydrae Cha- os, d) Area upstream of Ravi Vallis (Northeast of this
image), and Shalbatana Vallis (North of this image) with fractures and depressions.
FRACTURES BY GROUNDWATER?
• Several fractures features on Mars
• Pattern similar to experiments
• Other processes (volcanic) are possible
Figure 9: Schematic cross-section from Valles Marineris showing the location of different types of outflow features. Values correspond with groundwater head above surface and corresponding pressure in case of a confined aquifer with a pressure head at 4 km, which is equivalent to a source lake at that elevation.
