On the foreshock cascade and extraordinary forecasts in connection with the article by A.I. Malyshev and L.K. Malysheva “Precedent-extrapolation estimate of the seismic hazard in the Sakhalin and the Southern Kurils region”

Not so many issues, that have such a divergence of view, as on the existence and nature of foreshock activation. The range here is from public admission, that the previously described effect of foreshock avalanche-like activation is nothing more than the result of (though unconscious) data fitting, to the cases of incredibly accurate predictions of the time of strong earthquakes (though retrospective). The article by A.I. Malyshev and L.K. Malysheva, published in the current issue, gave a reason to return to these disagreements again and to offer a possible explanation for them.

Precedent-extrapolation estimate of the seismic hazard in the Sakhalin and the Southern Kurils region

The paper describes the algorithm and the results of the seismic hazard estimate in the Sakhalin and Southern Kurils region based on the data of the Japan Regional Catalogue (JMA). A nonlinear differential equation of the second order is used as a mathematical model, and algorithms for optimization and predictability estimation are presented by the author's solutions. The forecasting algorithm is based on the search for seismic activity zones in which the current activity trends correspond to foreshock sequences recorded before strong earthquakes (precedents) that have already occurred. The earthquake time is calculated with extrapolating the detected trends to the level of activity that occurred at the time of the precedent earthquake. By the example of precedent foreshock sequences in Japan, it is shown that the lead time of such a forecast reaches 10–15 years and its implementation is due to the preservation and stability of the identified trends. A map of potentially dangerous zones for Sakhalin and the Kuril Islands and some examples of calculating the time of strong earthquakes according to the JMA catalogue as of August 31, 2018 are presented. Action sequence in identifying the potentially dangerous trends in seismic activity and the specifics of possible use of the technique in the Sakhalin region are considered.

Analysis on the Definition of Japanese Territory After World War II in Terms of International Law: the Southern Kurils, the Diaoyu Islands and Tok Islet

Geopolitical tensions have periodically risen in the Asia-Pacific region due to territorial disputes between Japan and its neighbours over the Southern Kurils (the Northern Territories), the Diaoyu Islands (the Senkaku islands) and Tok Islet (Tok Islet (Dokdo)/ Takeshima). There is, of course, great discrepancy between the disputes over the Southern Kurils, the Diaoyu Islands and Tok Islet (Dokdo) in terms of their respective origin and legal nature, and effective control over them, and the historical and legal grounds on which the disputing states rely in their claims over the disputed territories vary widely. But what is consensual and definite is the fact that the islands in dispute were already excluded from the Japanese territory under the international legal acts deciding Japanese territory after World War II. The paper examines and analyzes Japanese reasoning behind its claim over the disputed territories in terms of relevant international legal acts relating to the delimitation of Japanese territory after World War II.

Status of the Southern Kurils: Issues of History and Problems of Ensuring Russias National Interests

Introduction. After the end of World War II, a peace treaty between Russia and Japan was never signed. The reason for this lies in the dispute between the two states about the ownership of the Southern Kurils. The intensification of Russian-Japanese negotiations on this issue in recent years actualizes the topic of this study in the context of ensuring the interests of Russia and the inviolability of its territory. Methods and materials. In this paper, the authors use the following methods: interdisciplinary historical, formal-logical, formal-legal. The use of forecasting and modeling methods contributes to the formulation of the main conclusions of the study. The theoretical basis of the research is presented by monographs and scientific articles on the history of Russian-Japanese relations over the Southern Kurils. Analysis. The paper presents the experience of relations between Russia and Japan since the mid-19th century. The basic international treaties that laid the legal basis for the territorial affiliation of the Southern Kurils have been studied in detail. The current state of the Russian-Japanese relations over the Southern Kurils has been analyzed. Japans claims to the Southern Kurils have been assessed in terms of the territorial and economic aspects. Results. The authors conclude that the territorial belonging of the Southern Kuril Islands was recognized by the international community of states as a whole on the basis of provisions of treaties in force at the time of concluding the Joint Declaration of the USSR and Japan of 1956, which entails the nullity of paragraph 2 of clause 9 of this Declaration. The inclusion of provisions on the non-separability of Russian territories in the Russian Constitution requires legislative concretization of the inadmissibility of territorial concessions by Russia in case of the conclusion of a peace treaty with Japan. The conclusion of a peace treaty based on the results of the agreements reached during the negotiations is also possible under other conditions that are not limited to the transfer of the Southern Kurils to Japan. In particular, it is possible to follow the path of economic integration of the respective territories by both countries.

The largest lakes of the Kuril Islands: morphometry and geographical distribution (materials for the database)

The work presents modern data on the location, morphometry, and genesis of the largest lakes basins of the Kuril Islands obtained in the volcanological expeditions of the IMGG FEB RAS during 2005– 2018 and using open geographic information resources. 1099 lakes were sampled according to the criterion S ≥ 1 km², the list of studied objects included 20 reservoirs, represented by 7 volcanic and 13 lagoon lakes. The considered lakes are clearly divided according to their origin, area and height of the mirror, and maximum depth. The most part of large lakes falls on the Southern Kurils, and the largest water body – the volcanic lake Koltsevoe – is located on Onekotan Island, which is a part of the group of the Northern Kurils. Volcanic lakes occupy an area of 48.26 km² (60 % of the total area of 20 lakes), the depth varies in the range from several tens to several hundred meters. This category of lakes is characterized by relatively high levels of the mirror, which range from 50 to 648 m above sea level. Lagoon lakes occupy an area of 32.15 km² (40 % of the total area of 20 lakes), the depth of water bodies is small – from 1 to 23 m, the absolute height of the lake mirror is from 1–5 to 8–9 m.