1. Georadar surveys of Lake Chebarkul in Russia were conducted to locate fragments of the Chelyabinsk meteorite that witnesses reported falling into the lake. 2. The surveys identified an anomaly on the lake bottom with a sharp drop in topography and disruption of the ice layer, which is interpreted as the impact crater from a meteorite fragment. 3. Further evidence supporting the meteorite impact hypothesis includes the meteorite's trajectory approaching the lake from the northeast and ejection of ice around the impact site.

1. Georadar survey of the crash site Chebarkul of the
meteorite fragment "Chelyabinsk"
V.V. Kopeikin, P.A. Morozov A.V. Popov (IZMIRAN), S.V.
Merkulov (VNIISMI), V.A. Alekseev (TRINITY)

2. Attempts to find a meteorite in the bottom of the lake in the vicinity of open water
were unsuccessful, although scientists and local residents removed from the
hole using a magnet small fragments with significant iron content. The depth of
the lake in the vicinity of a meteorite about 10 meters, divers made it difficult to
work the thick layer of loose silt, reaching at their estimated depth two or more
meters.
According to witnesses one of the largest meteorite fragments "Chelyabinsk"
February 15, 2013 fell in the western part of the lake Chebarkul,
leaving in the ice oval
wormwood sized 6x8 m.

3. To clarify the probable location of the Chebarcul fragment, was carried out a remote sensing
of the lake bottom with GPR "Loza-H", developed at the Institute of Terrestrial Magnetism,
Ionosphere and Radio Wave Propagation. NV Pushkov (IZMIRAN) Ltd. and produced by
VNIISMI
The principle of operation is based on the GPR
radiation of ultra-wideband electromagnetic pulses
in the underlying environment and recording their
reflections from the interfaces between the layers
or objects
A distinctive feature of the instrument series
"LOZA", compared with foreign and domestic
counterparts, is a great energy potential, allowing
to work in environments with high conductivity,
such as clay loam or wet
The probe pulse is generated by high-voltage gas
discharge tube (5-10 kV) and radiated resistor
loaded dipole antenna length of 0.5 to 6 meters.
A similar antenna is used in the receiver
«LOZA-V»,
«LOZA-N»,
Depending on the model of the
device and environment settings
probing depth ranges from a few
to hundreds of meters

4. During the three days of field work (12-14
March 2013) the expedition IZMIRAN-
VNIISMI produced 36 GPR profiles length
of 100-150 m in the area of the meteorite.
The grid covers the wormwood and the
area of 100x100 m to the west of it.
Sounding produced from the surface of the
ice allowed restore a detailed picture of the
bottom topography and indicate the most
likely place of occurrence of a meteorite or
its fragments
Furthermore, in the area of incidence, water
samples and the fine fraction of the ice fragments
were collected for further analysis of the physico-
chemical

5. Below is a sample representation of the raw data of GPR
sensing program "Krot1301" developed VNIISMI. The right
panel is a waveform pulses detected by the receiver in the
selected GPR profile point (A-scan). With the passage of the
track are formed in vertical sections (B-scan), shown in the
two left panels. Horizontal postponed distance in meters
vertically - the time of arrival of the reflected pulse in
nanoseconds (right scale) and the estimated depth of the
reflecting boundary (left scale)
Р602 Р603
Bands in the top of the picture correspond to the direct signal propagating from the transmitting to the receiving
antenna at different speeds - in the air, in the thick snow and in the water beneath the ice. Underlying the broad bands
correspond lengthy unipolar pulses reflected from a smooth transition from the sludge to the bottom of the solid rocks.
Bands in the top of the picture correspond to the direct signal propagating from the transmitting to the receiving
antenna at different speeds - in the air, in the thick snow and in the water beneath the ice. Underlying the broad bands
correspond lengthy unipolar pulses reflected from a smooth transition from the sludge to the bottom of the solid rocks.
Noteworthy is a violation of the structure of the ice cover and a sharp drop in the bottom topography on the profile
P602 at the intersection with the profile of R603.
We interpret this anomaly as the result of a meteorite impact on the bottom of the lake. Noteworthy is a violation of the
structure of the ice cover and a sharp drop in the bottom topography on the profile P602 at the intersection with the
profile of R603.

6. Further confirmation of this hypothesis are the observational
facts. Apparently, it is generally accepted that the Chebarkul
meteorite fragments approached the lake in the north-east
direction with an azimuth of 280-290 degrees inclined path.
Therefore, look for it at the bottom of tracks necessary to the west
of the polynya (open areas in frozen seas). A small amount of the
ejected ice around polynyas suggests that the bulk of its mass
was infatuated with a meteorite, and then surfaced, breaking the
structure of the ice cover over the funnel.
Based on this fact, we conducted a detailed areal sensing portion bottom situated between the shore
and wormwood. Linear profiles processed by the program "Krot" and 3D reconstruction of the bottom
topography reveal a dramatic deepening in this sector is likely caused by the fall of a meteorite
fragment. Further confidence can give a comparison with the magnetic measurements

7. 3D model of the surface of the bottom of the river,
with traces of the fall and the crater.