Examination of a giant crater in the Yamal Peninsula, Russia
November 12, 2014
The crater in the Yamalo-Nenets Autonomous District, November 2014.
Helicopter pilots, monitoring the oil and gas fields, discovered the giant crater on the Yamal Peninsula in July 2014.
In his article, published in The Drilling and Oil magazine in October 2014, Vasiliy Bogoyavlenskiy, corresponding member of the Russian Academy of Sciences, Ph.D., stated that the hole is estimated to be about 37 and 25 meters wide at its top and bottom accordingly and 41 meters deep with the last 5 meters flooded and covered with some rock, which has fallen to the bottom. The crater is assumed to be a result of an underground gas explosion.
The Russian Centre for Arctic exploration in Salekhard town is responsible for organizing the research of the crater to understand its nature and formation mechanisms.
On November 9, 2014, researchers descended into the bottom of the crater to take photographs of it from the inside and to take the soil and ice samples. Alexei Sherstnyov, our expert was a part of the research team. With the assistance of his colleagues from other organizations, he carried out GPR survey of the area around the sinkhole and its bottom using GROT 12 and GROT 12H georadars.
TASS Russian News agency gives the words of Vladimir Pushkarev, director of Russian Center of Arctic exploration, who said that the research group were the first ones to descend into the crater. He stated its shape, which resembled a cone, shocked them and the walls of the crater consist mostly of ice with intermixtures of rocks. The scientists could see that in the summer water had flowed down the walls of the crater and its bottom had turned into a small frozen lake so they could walk on it and take soil samples for research.
The research was carried out in just a few hours because of the snowstorm, which prevented the group from coming to the site earlier and staying there longer. But for short deploy time of our GPR equipment and hard work of Alexei Sherstnyov, Vladimir Pushkarev, Igor Bogoyavlenskiy and other researchers no GPR survey data suitable for processing would be obtained.
Fig. 1. Alexei Sherstnyov with GROT 12 georadar and 10 meter long antennas on the breastwork.
The study was conducted using flexible 10 and 2 meter long antennas on the surface and at the bottom of the crater accordingly.
The use of Bluetooth reduced the time of scanning and the number of people involved in the process. We would like to sincerely thank all who assisted us on the expedition.
Fig. 2. GPR scanning on the surface of the crater with 12 and 10 meter long antennas.
While working on the surface, Alexei Sherstnyov decided to carry out GPR scanning on several tracks around the crater. The tracks are marked on Fig. 3:
Fig. 3. GROT 12 tracks on the surface.
Fig. 4. Descent into the crater with gpr.
Fig. 5. Alexei Sherstnyov with GROT 12H georadar immediately after the descent into the crater.
Fig. 6. GPR works on the bottom of the crater.
Fig. 7. Climbing to the surface.
The data from scanning about 1000 meters of tracks with measurements taken at 651 points allowed determining the boundaries between media with different permittivity around and inside the crater.
Understanding the nature of the hole and its formation mechanisms as well as identifying potential threats of new hazardous objects in cryolithic zone requires application of a system of geophysical methods.
The received data analysis indicated that great depths GPR technology, which we have been developing for many years, can be one of the main geophysical methods of the permafrost section upper part examination.