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. . 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. For a more detailed discussion of the Dry Valley geomorphology, please refer to the Silica Enigma Dry Valley page.
The geographic location has been located 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.
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.