1. Samos, GR 1.1 Physical Geography / Geology of Samos, Greece -- June 6, 2016

The island of Samos is one of a series of easternmost islands of Greece, located in the eastern portion of the Aegean Sea close to the Turkish mainland (see map below). For this reason these islands serve as major draw for migrants coming from the Turkish mainland. As explained before, I will concentrate on Samos only. Looking at physiogeographic factors I will first explore why most refugees appear at certain spots on Samos island which does NOT coincide with the narrowest route between Samos and Turkey.

Greece and Turkey with the island of Samos in the Aegean Sea (source: Google Earth)

A close-up of the Google Earth image shows the close proximity of the island to Turkish Anatolia, the mainland. The bay formed by Samos and the Turkish mainland is commonly referred to as the Gulf of Kusadasi after the name of the Turkish city.

The island of Samos and the location of Kokkari (source: Google Earth)

The straight between Samos and Turkey, the Samos or Mycale Straight, is, according to several sources, about 1.65 km wide at its narrowest point. This close proximity has its explanation  in the fact that Samos disconnected from Anatolia due to earthquake activity. The latter is a consequence of major local plate movements and collisions as shown in the map below.

From: Long-term evolution of the North Anatolian Fault: new constraints from its eastern termination. 
Retrieved from sp.lyellcollection.org

The Aegean arc or Hellenic Arc is a complex tectonic feature of the Mediterranean Sea which is caused by the African Plate subducting (ASZ on the map) underneath the Aegean Sea Plate. Frequent earthquake and volcanic activity are the consequence.

This map found on Wikipedia illustrates where volcanism and earthquakes can be expected in the Aegean Sea; note that Samos is located north of the active volcanic arc which also includes the famous Santorini island.

By Mikenorton (2010). Tectonic map of the Hellenic arc taken from various sources,
 especially Chamot-Rooke et al. 2005 based on a screenshot from NASA WorldWind software

The area around Samos has seen about nine earthquakes greater than 6 on the Richter scale in the last two hundred years; the last major one occurred in 1904. The map below shows the fault line

extending from Anatolia to the island.

ÖMER FEYZI GÜRER, ERCAN SANGU and MUZAFFER ÖZBURAN (2006). 
Neotectonics of the SW Marmara region. Geological Magazine, Vol. 143, issue 02, 03 2006, pp. 229-241.

The island Samos itself has been classified as a tilted horst (see graph to the left) with its highest elevation in the NW corner and a 1,000 m deep basin (on the graph indicate as 'graben') located on the northwestern side;  a fault runs between the mountainous NW coast and the basin. Stiros et al. interpret the uplifted shorelines found on the island as correlating with Holocene (starting at about 11,700 years ago) earthquake activity; this is further cemented by findings of certain fossils as well as radiocarbon analyses on elevated shore and platform sites indicating a rapid drop in sea level



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Sources:
Stiros, S.C., Laborelb, J., Labrel-Deguenb, F, Papageorgiouc, S., Evind J and Pirazzolie, P.a. (2000). Seismic coastal uplift in a region of subsidence: Holocene raised shorelines of Samos Island, Aegean Sea, Greece. Marine Geology, 170, pp. 41-58.

(2007) Geomorphology and Holocene Uplift of Northwestern Samos. Journal of the Virtual Explorer. Retrieved from http://www.virtualexplorer.com.au/article/2007/180/excursions-on-samos/geomorphology.html