RU2577917C1 - Method of determining point of formation of icebergs of outlet glaciers - Google Patents

Abstract

FIELD: geography.

SUBSTANCE: invention relates to methods of remote investigations of glaciers and can be used to determine places of possible formation of icebergs of outlet glaciers. Method comprises obtaining an image of surface of a glacier or visual observation thereof from airplane or helicopter. Method includes selecting course of surface water flow on surface of glacier. Exit of said flow to boundary of glacier is taken as starting point of ice body and possible formation of icebergs.

EFFECT: technical result is determination of place of calving (separating from the array of glacier) icebergs of outlet glacier.

1 cl, 4 dwg

Description

The invention relates to the field of geophysics and remote sensing and can be used to predict the time and coordinates of the formation of icebergs of output glaciers.

There is a method of determining the movement of a glacier with the subsequent fall of a certain amount of ice in the sea and fixing this event with a seismometer installed on the shore and a waveograph located on landfast ice [1, 2]. This method allows you to determine the moment of formation of the iceberg by the time of entry of the elastic wave, which propagates along the ground (microseisms) when the iceberg breaks off the glacier and collapses into the sea. And from the water (gravitational) wave that forms in the sea, with the help of a waveograph, you can determine the very fact of the formation of an iceberg.

The disadvantage of this method is the inability to determine the coordinates of the place of formation of icebergs and the need for a stable landfast ice in the region of their formation. However, in the winter time fast ice can be unstable, in summer it is completely absent.

There is a method of determining the time and coordinates of the formation of icebergs of output glaciers [3], which consists in the fact that seismometers and waveographs are simultaneously used to determine these values when three seismometric stations (each consisting of three seismometers - two horizontal and one vertical) are installed triangular a pattern at the vertices of a triangle with sides of at least 200 m on mainland soil, while horizontal seismometers are oriented to the cardinal points - north-south and west-east. As a result of the fact that the waveograph is placed on the bottom soil in the iceberg formation area with the possibility of transmitting a signal via cable to the transmitting antenna, all ice blocks that have broken off from the ice massif are recorded - both icebergs and pieces of various sizes, and the iceberg calving is falsely recorded. This is the disadvantage of the method.

Along with this, a method is known that performs the determination of sea ice parameters using electromagnetic waves of different frequency ranges, in which the technical result consists in obtaining satellite radar images and images in the optical wavelength range [4].

Known is taken as a prototype method for detecting icebergs [5], which includes obtaining a signal of satellite images of radar images and images in the optical wavelength range, performing an analysis of the brightness of elements of radar images, identifying zones of anomalous values of the radar image signal by comparing it with a reference, predicting the movement of the anomalous zone between sessions of receiving information and comparing the observed position with the predicted; if the trajectory of the zone of signal anomaly coincides with the predicted trajectory of the iceberg, a decision is made about the presence of the iceberg.

The disadvantage of this method is the inability to predict the place and time of formation of icebergs.

The proposed method is based on the regularity established by the authors of the formation of a mass of frozen ice in the outlet glacier, the essence of which is illustrated by photographs of the surface of the glacier obtained from a helicopter in the process of flying around the glacier, shown in FIG. 1-3.

In FIG. 1 in the picture a) the image of the glacier surface is shown, in the picture b) the image of the glacier surface in the region of the surface water flow is shown.

In FIG. 2 in the picture a) a close-up shows the image of the surface of the glacier in the region of the surface water flow, the picture b) shows the image of the surface of the glacier when it reaches the surface of the water.

In FIG. Figure 3 shows the image of the boundary of the Novaya Zemlya glacier, obtained from the spacecraft, where it is indicated:

1 - the boundary of the outlet of the water flow on the glacier,

2 - icebergs, on top of which you can see the image of the channel of the glacier’s water flow,

3 - region of ice formed by the destruction of the glacier not in the zone of action of the water flow.

In FIG. 4 shows the image of the border of the Argentine glacier obtained from the spacecraft, where it is indicated:

1 - the boundary of the outlet of the water flow on the glacier,

2 - icebergs, on top of which you can see the image of the channel of the glacier’s water flow.

The pattern of formation of icebergs of output glaciers is that water moving on the surface of the glacier with a water stream fills cracks, freezes, and thus “cementes” individual ice floes that form when the massif of the glacier is split. Thus, approaching the edge of the glacier, such an ice massif creates an iceberg. This is confirmed by the images of icebergs (2) containing drawings of a part of the water stream (1), which are absent on the ice floes that have broken away from the part of the glacier that does not contain the surface water stream (3).

Considering the indicated regularity, the technical result is the determination of the position of the calving (separation from the massif of the glacier) of the iceberg of the glacier containing the outlet of the water flow to the border.

The method for determining the place of formation of icebergs of output glaciers consists in detecting on the ice image the place where the water flow exits to the border of the glacier and is carried out as follows.

A signal is received from a remote sensing spacecraft, or a glacier surface is observed from an airplane or helicopter.

The signal is recorded in the form of an image of the surface of the glacier and brightness analysis of image elements is performed. When flying around a glacier, the channel of the water flow on the surface of the glacier is visually distinguished, or by analyzing the image, a place is identified where the water flow approaches the boundary of the glacier.

The indicated place is identified by the pattern of the glacier bed as the place of a possible iceberg formation.

Information sources

1. Smirnov V.N., Korostelev V.G., Shushlebin A.I. Monitoring of the dynamics of fast ice and icebergs. Proceedings 17-th Int. Conf. on Port and Ocean Eng. under Arctic Conditions (POAC 03), pp. 709-713.

2. Smirnov V.Η. On the bending-gravitational vibrations of the ice cover of the Davis Sea. Bull. Owls Antarctic Exp. No. 61, 1967, p. 61-65.

3. RU 2427011 C1, publ. 08/20/2011.

4. SU 1788487 A1, publ. 01/15/1993.

5. RU 2506614 C2, publ. 02/10/2014.

Claims (1)

A method for detecting icebergs of output glaciers, including receiving a signal from satellite images of a glacier surface or making visual observations from an airplane or helicopter on a glacier surface, registering a signal in the form of images of a glacier surface, analyzing the brightness of image elements or visualizing a channel of a water stream on a glacier surface, characterized in that the images or visually search for the exit point of the surface water flow to the border of the glacier by ozhdeniya inherent in this place the figure, which is taken place for the separation of ice mass and the possible formation of icebergs.

Images