The Active Faults of Eurasia Database

Abstract

This paper describes the technique used to create and maintain the Active Faults of Eurasia Database (AFED) based on the uniform format that ensures integrating the materials accumulated by many researchers, including the authors of the AFED. The AFED includes the data on more than 20 thousand objects: faults, fault zones and associated structural forms that show the signs of latest displacements in the Late Pleistocene and Holocene. The geographical coordinates are given for each object. The AFED scale is 1:500000; the demonstration scale is 1:1000000. For each object, the AFED shows two kinds of characteristics: justification attributes, and estimated attributes. The justification attributes inform the AFED user about an object: the object's name; morphology; kinematics; the amplitudes of displacement for different periods of time; displacement rates estimated from the amplitudes; the age of the latest recorded signs of activity, seismicity and paleoseismicity; the relationship of the given objects with the parameters of crustal earthquakes; etc. The sources of information are listed in the AFED appendix. The estimated attributes are represented by the system of indices reflecting the fault kinematics according to the classification of the faults by types, as accepted in structural geology, and includes three ranks of the Late Quaternary movements and four degrees of reliability of identifying the structures as active ones. With reference to the indices, the objects can be compared with each other, considering any of the attributes, or with any other digitized information. The comparison can be performed by any GIS software. The AFED is an efficient tool for obtaining the information on the faults and solving general problems, such as thematic mapping, determining the parameters of modern geodynamic processes, estimating seismic and other geodynamic hazards, identifying the tectonic development trends in the Pliocene-Quaternary stage of the Earth's development, etc. The Active Faults of Eurasia Database is created in the format providing for inputs of new information, as well the database updating and revision.

The Velocities of Modern Horizontal Movements of Earth Crust in the South Sector of Yenisei Ridge According to GNSS Observations

“…The model obtained is consistent with the results of structural-geological and geodynamic studies in the area [6][7][8]10]. The velocity of approach of the Siberian Platform and the West Siberian Plate in their interaction zone within the southern Yenisei Ridge can be estimated at 2-4 mm/yr.…”

“…Figure 2 shows the field of average annual velocities of horizontal MCMs and the result of their kinematic interpretation. The study area is subdivided into 13 large structural blocks, separated in most cases by large tectonic faults identified earlier from geological data [6,10].…”

Using the Active Faults of Eurasia Database for solving tectonic problems

“…В рамках выполненного исследования для каждой области принимались в расчет все разломы, содержащиеся в БД, причем разломы, предположительно активные (категории достоверности CONF C и D), учитывались с меньшим весом, чем достоверные разломы категорий A и B. Это оправдано при изучении разломных движений позднеплейстоцен-голоценового возраста, поскольку нивелирует фактор недостаточно надежных и, возможно, даже ошибочных сведений, содержащихся в БД. Однако, согласно методике составления БД [Bachmanov et al, 2017], в качестве предположительно активных разломов с достоверностью C и D нередко выделялись нарушения с выразительными проявлениями подвижек плиоцен-раннечетвертичного возраста, но ненадежными и фрагментарно выраженными признаками позднечетвертичной активности (в отличие от достоверных категорий A и B, где наиболее выразительны проявления именно позднечетвертичных движений). В связи с этим в тех областях, где преобладают предположительно активные разломы (C-D), роза-диаграммы характеризуют в большей степени плиоцен-раннечетвертичную, чем позднечетвертичную, активность.…”

“…Принципы составления и формат содержания базы данных активных разломов Евразии подробно изложены в статье [Bachmanov et al, 2017]. Цель предлагаемой статьи -на примере отдельных конкретных вариантов компьютерной обработки БД показать значение, возможности и перспективы программного использования больших массивов цифровых данных по активным разломам для решения тектонических и геодинамических задач.…”

The Database of the Active Faults of Eurasia (AFEAD): Ontology and Design behind the Continental-Scale Dataset

“…All these issues required creating a conceptually new database, and this work was initiated based on DB96 some 15 years ago (Bachmanov et al, 2017). The authors have designed the new database and GIS for data processing that inherited all the strengths of DB96 but provided far more opportunities for parameterization and analysis.…”