Archaeologists developed the Late Bronze Age chronologies of eastern Mediterranean cultures by analysing the origin of artifacts (for example, items from Crete, mainland Greece, Cyprus or Canaan) found in each archaeological layer. If an artifact's origin can be accurately dated, it gives a reference date for the layer in which it is found. If the Thera eruption could be associated with a given layer of Cretan (or other) culture, chronologists could use the date of that layer to date the eruption itself. Since Thera's culture at the time of destruction was similar to the Late Minoan IA (LMIA) culture on Crete, LMIA is the baseline to establish chronology elsewhere. The eruption also aligns with Late Cycladic I (LCI) and Late Helladic I (LHI) cultures, but predates Peloponnesian LHI. Archeological digs on Akrotiri have also yielded fragments of nine Syro-Palestinian Middle Bronze II (MBII) gypsum vessels.