On the earthquakes in the Northern Baltic Shield in the spring of 1626

This study starts from the earthquakes of May 14, 1626 and June 22, 1626 as given in existing parametric catalogs for the Baltic (Fennoscandian) Shield. The first shock is located in North-western Russia, the second in Finland that belonged to Sweden at that time. A search for previously unknown Russian sources of information is performed, and secondary Swedish sources are replaced by primary ones. The contemporary sources are two Russian chronicles and two Swedish manuscripts. In addition, a later reminiscence is used. The contents of the sources are critically analyzed and augmented with background information. A new interpretation of one Swedish manuscript is presented. The earthquake dates are analyzed. A credible source of errors follows from the different calendars used. Macroseismic intensity assessment is possible for two places. A new solution of one earthquake felt in both territories is proposed. The available data are too fragmentary to prove it beyond doubt, but the scenario is feasible in many ways. Tentative earthquake parameters are calculated. Epicentral intensity is assessed at 6–7 (EMS), magnitude is estimated at 4.7–5.7. The epicenter is located in Russia close to the border between the two territories. Copyright Springer Science+Business Media B.V. 2011