15 
4 Historic tsunami affecting the North Sea 
The tsunami of December 2004 gave rise to a discussion on possible tsunami in the North 
Sea, mainly because it hit the coastal and island population completely unprepared. No 
collective memory of a tsunami event existed although major tsunami had occurred in this 
region in the not too distant past. The Krakatoa volcano erupted in 1883. Then, in 1907, a 
tsunami of intensity 4 (on a scale from -5 to +5; from 2001: scale from 1 to 12) caused 400 
deaths. In 1941, another tsunami of intensity 4 in the Andaman Sea north of Sumatra had a 
death toll of 5,000 (10.2: NGDC). 
Prior to the event of December 2004, the German public and many scientists saw no 
association between tsunami and the North Sea. Therefore, historic tsunami events affecting 
the North Sea will be outlined in the following. 
The most recent major tsunami which travelled as far as the North Sea were the tsunami 
caused by a slope failure off Newfoundland (1929) and that triggered by the Lisbon 
earthquake in 1755. However, it is primarily the proven impact of the Storegga slide which 
has raised the awareness of a potential threat. It dates back about 8,000 years and probably 
contributed to the destruction of the land bridge between Denmark and England (Derbyshire 
et al. 2003). 
65 million years ago, a meteoritic impact off Yucatan (Mexico) caused a devastating tsunami 
in the prehistoric Atlantic Ocean. However, the region now covered by the North Sea was 
affected only by the climatic change caused by the meteoritic impact. A much smaller 
asteroid hit the prehistoric North Sea 65-60 million years ago. The Mjolnir impact was about 
140 million years ago. Part of the Paleo-North Sea (Ziegler 1990) is included in model 
simulations (Glimsdal et al. 2007). 
Since 1952, several smaller tsunami have been recorded in Norwegian fjords, the most 
recent one in 1999 (Maramai et al. 2003). The most recent entries in the Russian database, 
with the source region Iceland, date back to 1924 and 1934. 
The North Sea earthquakes of 1927 and 1931 discussed in the UK report (Kerridge 2005) did 
not even cause local-scale tsunami.