The Ronne Series
The Ronne Ice Shelf in the Antarctic faces the Weddell Sea at longitude 60º West. Embedded within its seaward edge is a proposed PZ Terminal Fan Crater structure. Let us explore the process of locating and identifying it. The Google Earth KMZ file "Ronne_Series" is available from the KMZ download page.
This proof set began with the tentative identification of central Turkey as a PZ Mega Ejecta emplacement site. This identification was drive by several factors:
- The general shape of the country of Turkey is identified as an accretive assembly of PZ ejecta characteristic teardrop shapes.
- The central ejecta shape has a significant body of water centrally located. This is lake Tuz, and the GE placemark is so named
- The location of Turkey is identified elsewhere in the PZ proof sets as being excavated during a PZ Trench Crater event which created the Black Sea.
- The island of Cyprus, strongly aligned within the Ejecta matrix on the platform of Turkey, is identified in a PZ proof set as being emplaced during the PZ series
The emplacement is 460 Km wide, and 726 km long. the indicated arrival azimuth is 8º
.
Lake Tuz, Turkey
Shown with other
components
To validate the identification, we follow the azimuth of the emplacement back across the globe. The great circle route north on azimuth 8º crosses the Northern coast of Russia and enters the Kara Sea. This body of water is separated from the Arctic ocean on the North by an island, a geometric arc of land know as Nova Zemlya. This remote, inhospitable land was used by Russia as a location for nuclear testing. The geometrically crisp inner coastline makes this strongly indicative of being a PZ structure. The PZ generic Trench Crater overlay sets well into the structure between the island and the north coast of Russia, as shown here. We measure the structure as 640 km long and 275 km wide.
Kara Sea PZ Trench Crater
Corroborating evidence is found in the form of the nearby Kolguyev island. This structure, 100 km on the major axis, lies 300 km down range from the Kara Sea Crater terminus. The shape is a classic PZ ejecta landform.
Kolguyev
islandAt this point in our review, we feel the evidence is strongly supportive that the Kara Sea structure is a PZ cometary impact structure. To continue the process, we will look backwards and forwards in time to attempt discovery of other PZ crater structures associated with comet impactor that created the Trench at the Kara Sea. The hypothesis maintains the trench craters are created at Perigee: Zero interfaces, and as such the comet body has been nearing the surface of the earth in previous orbits. Subsequent to this trenching episode, the comet body continued on to strike elsewhere on the next orbit.
First we examine the previous orbit, where we expect any cratering indications to appear approximately 90 minutes (one orbit time) easterly from this crater. That equates to 22.5 minutes of longitude, and should lie along a great circle line that is normal to the center of the orbit track through the center of the Kara Sea structure. On first examination, nothing significant is seen at the expected location.
Given that the area is at sea level, we do a test try on the previous orbit, another 22.5 degrees longitude easterly. Reviewing the globe, we locate a potential target in the form of a bruise, which we name the Yessey PZ Bruise. The structures measures 500 km long by 280 km wide, bearing 52º. The geometry and orientation are evaluated and a decision is made that the structure fits into the Ronne set. A very distinctive fan of damage and debris can be seen radiating out from the downrange terminus of the bruise in the photo shown here.
Yessey Bruise
A search further east for PZ impacts on previous orbits was negative. However, we did revisit the first Kara Sea -1 orbit location, and can now identify a slight bruising near Dikson, Russia. This identification can be made in confidence given the correlation with Yessey and Kara structures. Ground studies may help secure a higher level of confidence. We note that the Yessey bruise was on terrain that is (now) at approximately 700 m elevation. The Dikson Bruise is primarily at less than 100 m. We interpret this to suggest that the perigee of the orbit crossing over Dikson was 600 m lower. Much good science can be done with those two numbers!
Dikson Bruise
Moving on back to the Kara Sea structure, we will investigate where the comet went on its orbits after the PZ Trenching event there. Experience from this research has shown that an event of this magnitude - a major crater and a Mega "divot" of PZ Ejecta lofted thousands of kilometers down range - will remove substantial momentum from the comet body. It is likely that another full orbit will not be accomplished, and the comet body will terminate in a PZ Fan crater.
A review of the next orbit locale 22.5 degrees longitude westward is in the Barents Sea, where no indications were found. Research proceeded by following the predicted orbit track from the Kara Sea Crater. Nothing of interest was noted until the track reached the Antarctic continent. After adjusting for the earth's rotation while transiting, a test case was attempted in the area of the Ronne Ice Shelf. This brings us back to where we started this discussion. Let us evaluate the data we collected from the Ronne PZ Terminal Crater impact. The structure is well-fit into an anomaly on the ice shelf, as can be seen in the Google Earth picture,below. It is approximately 530 km long and 560 km wide at the terminal end.
Ronne Terminal Crater
This fit gives us a high degree of confidence that the structure was created by an impacting comet body. Additional research on site may offer more positive proof. Given a confident fit, we can derive some additional data. During the sub-orbital transit from the Kara Sea Crater, the comet traveled 17,700 km. The actual great circle route would have placed the impact further east, and is identified as the back fan outline on the next photo.
Ronne Rotation
OffsetThere is a 40º earth rotation evident in the orientation data. This translates into approximately 160 of loft time for the sub-orbit. Given the travel distance, we can arrive at a figure of 6,650 km/hour average velocity for the transit.
Only one detail remains to be investigated. While a terminal crater is considered the final disruption of the cometary body, this event can also generate two types of ejecta. First is the expected terrestrial ejecta component. Some will be in the immediate area long the rims, and there may be a lofted component down range. Secondly, small cometary fragments may have broken free and continued, again in a sub-orbital track.
Subsequent to the initial proof development, we have identified the ejecta components from the Ronne PZ Terminal event. They are deposited on the opposite coast of Antarctica at the McMurdo Sound area. We offer a full presentation of the proof set of those ejecta in a separate chapter, under the Enigma topic. The manifestation of the remnant cometary material is seen as being deposited across a vast expanse of coastline at mcMurdo sound. The result is a true anomaly; please visit the "DRY Valleys" of McMurdo Sound.
The Google Earth KMZ file "Ronne_Series" is available from the KMZ download page.
