The respected Comrade
"We should make great efforts to develop new branches of cross-disciplinary sciences in line with the trend of the comprehensive development of science and technology and the demands of socio-economic development."
In this paper we have described the methods of drawing up the archeomagnetic reference curve and archeomagnetic map corresponding to Korean Peninsular region, by using international database.
An archeomagnetic reference curve is one on which geomagnetic elements (geomagnetic field intensity T, inclination I, declination D) depending on past ages in a particular area (exactly, any one point) are marked, and an archeomagnetic map is one which represents geomagnetic element's values of all points in any one age, any one area with contour lines.
The archeomagnetic reference curve has areal limitation and shows geomagnetic variation property depending on the age in a particular area, but archeomagnetic map reflects the distribution property of geomagnetic field of the whole area representing by it in corresponding age, for that reason, archeomagnetic map drawn by ages enables us to know geomagnetic field's variation property of the whole area.
For drawing up the archeomagnetic reference curve and archeomagnetic map, the geomagnetic field element values depending on the age in all points of corresponding area must be given. Such data may be given by direct archeomagnetic measurement, and may be determined analytically by using international archeomagnetic database.
Under the condition that is dense to the space-time, direct archeomagnetic measurement data has not been accumulated fully, we have been able to draw the archeomagnetic reference curve and archeomagnetic map corresponding to Korean Peninsular region by using international database, in the shortest possible period.
This is based on the fact that the geomagnetic phenomenon is global and, between any areas on the earth's surface, there is correct analytic connection, when we consider it only in first approximation. In other words, if the geomagnetic field element values (TA, IA, DA) in a particular area A(φA, λA) on the earth's surface are given, the geomagnetic field element values (TB, IB, DB) in another area B(φB, λB) can be determined.
From this, for drawing up the archeomagnetic reference curve and archeomagnetic map of Korean Peninsular territory, we have gone through the following steps.
We classified according to types international archeomagnetic databases published until now, and then from it induced the analytic expression with which geomagnetic element's values in a target area can be calculated.
In general, the data of international archeomagnetic database are published in 4 types. That is,
ㄱ) The values data of the geomagnetic moment M and paleomagnetic pole P(Φ0, Λ0) along with age.
ㄴ) The values data of TA, IA, DA along with age in area A(φA, λA)
ㄷ) The values data of IA, DA along with age in area A(φA, λA)
ㄹ) The values data of the paleomagnetic pole position P(Φ0, Λ0) along with age.
These are boiled down to the following 2 types in essence.
Type 1: the case where data of TA, IA, DA values along with age in area A (latitudeφA, longitude λA) are given.
Type 2: the case where data of IA, DA values along with age in area A (latitude φA, longitude λA) are given.
The method of drawing up of the archeomagnetic reference curve and archeomagnetic map by the data of type 1 is as follows.
From data of type 1, we find first derivative-first order Gaussian coefficient, g10,g11, h22 and then from it, we calculate geomagnetic elements TBi,IBi,DBi in all points Bi(φBi,λBi) of object area B (in this case, Korean Peninsula region).
These data are planimetric data corresponding to a target area. With planimetric data, by method taking the isolines, T-archeomagnetic map and I-archeomagnetic map, D-archeomagnetic map are drawn respectively. At this time, if T(or I or D) values corresponding to one point are arrayed chronologically then they are became archeomagnetic T(or I or D) curve respectively.
The method of drawing up the archeomagnetic reference curve and archeomagnetic map by the data of type 2 is as follows.
First, we calculate the paleomagnetic pole position P(Φ0, Λ0) from data of type 2.
Secondly, we calculate the values of T, I and D in all points of the area by taking arbitrary M(M>0). And by using this data we draw the I-archeomagnetic map and D-archeomagnetic map. In this case, the data of T values do not be used, because these are values which are calculated by virtual M value.
As considered above, drawing up of the archeomagnetic reference curve and archeomagnetic map corresponding to Korean Peninsula region by using the international archeomagnetic database is analytically possible.
Today, when archeomagnetic reference curve data and international archeomagnetic database have already been researched and published in various parts of the world and have been accumulated in large amount, the method above described is the analytical one which enables us to draw up the archeomagnetic reference curve and archeomagnetic map corresponding to target areas in a short period.
This method can also serve as an important tool capable of verification, estimation, prediction of correctness, reliability and tendency of archeomagnetic reference curve and archeomagnetic map in areas where their archeomagnetic reference curves and archeomagnetic maps have been or will be drawn up.
Since international archeomagnetic databases continue to be supplemented with new data, if the method above mentioned is employed, the archeomagnetic reference curve and archeomagnetic map can be updated and completed continuously.
