McMurdo Dry Valleys
The Perigee: Zero team has researched the geological and geographic data regarding the anomalous dry valleys in the McMurdo Sound region of the Antarctic. Here is a brief description of the area.
From McMurdo Dry Valleys LTER - MCM
The McMurdo Dry Valleys are located on the western coast of McMurdo Sound (77°00'S 162°52'E) and form the largest relatively ice-free area (approximately 4800 square kilometers) on the Antarctic continent. These ice-free areas of Antarctica display a sharp contrast to most other ecosystems in the world, which exist under far more moderate environmental conditions. The perennially ice-covered lakes, ephemeral streams and extensive areas of exposed soil within the McMurdo Dry Valleys are subject to low temperatures, limited precipitation and salt accumulation.
copyright William McLaughlin 1992-2004
The NSF has funded considerable sums of money to arrive at a solution for the anomalous conditions found in these valleys. One of the most interesting factors to us is the prevalence of deep silicate (sand) deposits throughout the area, and a veritable lack of deep snow cover.
The geographic location has been identified using Google Earth, and the site is clearly demarcated by the generic PZ Ejecta form. The structure is 340 km along the major axis, and 210 km wide. The arrival azimuth is 355º. The picture here presents the site with our overlay imposed in yellow.
McMurdo PZ Emplacements
Our interpretation is that the veneer of silicate provided a warm blanket which melted the snow originally beneath the area. This was perhaps from a combination of the ejecta initially high temperature, and the on-going adsorption of solar radiation. Note that in the area east of the centerline, the ejecta failed to destroy the ice cover, but a definitive smooth outline of the form remains visible. A neighboring, and corroborating, structure in the McMurdo Sound is shown with the pink overlay, although only it's down range tip is visible (image below), as the remainder of the emplacement likely burned through the Ross Ice sheet that hides it now. We expect that this can be verified by underwater sensing equipment and there should also be an associated demarcation trace across Ross island. The location and analysis of that trace may prove instrumental in analyzing the date of the event. Ross island is the manifestation of the volcano, Mt. Erebus, so lava flow interaction with the trace may offer dating clues. We note that the presence of "dry land" on Ross Island would normally be attributed to the actions of the volcano.
Ross island Emplacement tip
In the area we now look for other ejecta emplacements which exhibit similar alignment characteristics. further down-range, the projection from Antarctic which contains Mount Sabine is examined, and found to make a perfect fit-match with the generic ejecta outline, and with generally the same azimuth. The characteristic of this structure, is effectively defining the landform shape, is interpreted as a mega-emplacement, rather than a veneer coating as seen in the McMurdo ejecta. Differentiating the two, the Mt. Sabine mass is more dense, and carried further downrange due to conservation of momentum against atmospheric resistance.
Mount Sabine Mega Ejecta Emplacement
All PZ ejecta are related to the causal PZ impact crater by following the azimuth line back and correlating it with a know or proposed PZ Crater structure. in this case an immediate match was found with the terminal crater from the Ronne Series. [Reference our Proof Set for the Ronne Series] The alignments are shown in the Google earth image below. This Google earth snapshot has been augmented with a predicted great circle azimuth line from the point of impact. This gives a good approximation of the flight line of the primary ejecta components - straight down the orbital line - much like a golf divot travels.
McMurdo Sound PZ base Azimuth
The earth is rotating quite fast at the South Pole, so the rotation effect during the loft time becomes significant in ejecta emplacement location an orientation. We provide another graphic, this time with the flight path stationary, and the earth "rotated" beneath about the south pole axis. First we rationalize the ejecta emplacement at Mount Sabine emplacement. The rotation angle is measured at 22 degrees, which represents 88 minutes of flight time. The 3000 miles from Ronne crater were accomplished at an average velocity of 2,000 kph
Sabine Azimuth rotated 22º
Next we rationalize the original McMurdo Sound ejecta for position relative to Ronne. The graphic below illustrates the trajectory to McMurdo after rotation of 32º.
McMurdo Azimuth rotated 32º
This represents approximately two hours of flight time, minutes of flight time. The 2500 miles from Ronne crater were accomplished at an average velocity of 1,200 kph.
As a final graphic, we present a persecutive view of the flightline.
The graphics in this presentation are available in higher resolution in a portfolio, HERE.
Reference our Proof Set for the Ronne Series HERE
The Google Earth placemarks and overlays KML file can be downloaded from the KML download page. We encourage the reader to utilize Google Earth and these KML files to examine the alignment and overlay fit of each of these PZ landforms.
The enigma of the dry valleys of McMurdo Sound is evaluated for fit with the Perigee: Zero Hypothesis. We strongly suggests the proof given here identifies the area as being overlaid with a blanket of ejecta material from a PZ cometary impact at the Ronne Sea Shelf. The blanket, by way of it's initial high temperature, and by the long-lasting effect of its solar adsorption characteristics, have left the area devoid of deep snow cover.
Furthermore, given its demonstrated low density, we conclude the the majority of the silicate material found in the area is pure cometary material. This substance does not easily support flora, and hence the are is quite devoid of the expected plant life.