ACTIVE PROJECTS
Detecting the Seismic Signature of Titanian Fluvial Sediment Transport via Dragonfly’s Seismometer
Co-authors: Dr Samuel Birch.
Institution: Brown University Department of Earth, Environmental, and Planetary Sciences.
NASA’s exciting upcoming Dragonfly mission to Titan is projected to land in the Shangri-La dune fields in 2034 before transiting to Selk Crater. This location, however, is located far from the confirmed hydrocarbon lakes and rivers located on Titan’s poles, which are one of the most fascinating peculiarities about Titan given their familiar – yet alien – constitution. Studying Titan’s rivers is important because it not only allows us to test Earth based geomorphological empiricisms under these vastly different flow regimes, but also because it gives us insight into Titan’s climate. There may still be a way for us to study Titan’s rivers with Dragonfly as Selk Crater is hypothesised to potentially have hydrocarbon streams incised within its rims. Unfortunately, the crater rim is too steep for Dragonfly to safely traverse, so we must find a way to study Titan’s rivers without actually seeing them by using the seismometer aboard Dragonfly. By applying a model by Tsai et al. (2012) that was able to detect the seismic signature of fluvial sediment transport in Himalayan rivers using seismometers, we seek to help pave the way for the upcoming Dragonfly mission by determining if the DraGMet seismometer on Dragonfly is able to detect sediment transport in Titan’s methane rivers.
Fig 1. Selk Crater, the destination for the upcoming Dragonfly mission, as seen in Cassini VIMS (from Soderblom et al., 2010.)
PROPOSED PROJECTS
Fig. 2. Titan’s only two confirmed delta lobes, formed where Saraswati Flumen terminates into Ontario Lacus’ shoreline, as seen in Cassini SAR.
Titanian Delta Morphodynamics
Co-authors: Dr Samuel Birch, and Dr David Mohrig.
Institution: Brown University Department of Earth, Environmental, and Planetary Sciences.
At Brown University, I am working with Sam Birch on modelling Titanian geomorphology and morphodynamics by collaborating with David Mohrig and using his flume facilities at The University of Texas to investigate how the density change between the methane-nitrogen rivers flowing into the methane-ethane seas affects the geomorphology of Titan's deltas. This is important because in the Cassini SAR data of Titan, we can only see two deltas within the entire data set compared to the abundance of deltas on Earth, so perhaps the reasoning behind this is due to the vast density disparity between the seas and rivers, causing plunging currents which carry the sediment away from where a delta would be otherwise expected to form. In addition to flume modelling at UT, I will also potentially have the opportunity to conduct experiments at NASA JPL where we plan on cooling a test tube sized vial of liquid methane to Titanian temperatures to measure the settling velocity within the methane rivers.
Controls on Titanian Lacustrine Morphology
Co-authors: Dr Samuel Birch.
Institution: Brown University Department of Earth, Environmental, and Planetary Sciences.
Expanding upon my previous work on deriving the geomorphometric controls on minibasin morphology in the Gulf of Mexico, we are extending this analysis to Titan’s polar lakes – which bear remarkable morphological resemblance to the irregular type minibasins – in order to discover the governing controls on their morphology via implementing metrics such as the first eccentricity, rugosity, centroidal dispersion, rotation angle, etc.
Fig. 3. Small filled lakes in Titan’s northern polar lake district.
Fig. 4. Kraken Mare, the largest of Titan’s seas, and the largest lake in the solar system.
Titanian Oceanic Circulation
Co-authors: Dr Samuel Birch, and Dr. Abhinav Jindal.
Institution: Brown University Department of Earth, Environmental, and Planetary Sciences.
Due to the density and temperature disparity between the methane-nitrogen rivers flowing into the methane-ethane seas, in conjunction with the rivers primarily entering from the polar reaches of the latitudinally elongated seas with more significant evaporation occurring within the more equatorial reaches of the seas, it is postulated that this results in the generation and sustainment of oceanic currents within Titan’s seas, without the necessity of significant tidal forces. To test this hypothesis, work will be carried out on modelling this circulation via the employment of oceanic circulation models on an MIT supercomputer.