At the occasion of his 80th birthday the Swiss Geological Society honoured Ziegler with a symposium on the theme “Deep Earth - from Crust to Core”, held in Lugano, November 23, 2008.
2008 ehrte ihn die Schweizer geologische Gesellschaft mit einem Symposium zum 80. Geburtstag Deep Earth – from Crust to Core (Lugano, 23. November 2008).