Building a dome to stand through earthquakes

This lesson asks you to assess ways people reduce the harm that forces from nature do to structures, and to describe features and materials that let a structure withstand such forces. The museum offers one city building and what its builders changed after earthquakes. Rural and remote communities, other structures and the materials themselves are for your class to study. ¹

List what was changed in the building you read about, then say which change addressed the shape, which the supports and which the walls.

Build a small model from paper or blocks and shake the table. Decide in advance what you will watch for, and change one thing at a time.

When the emperor Justinian had Hagia Sophia rebuilt, he required that the new building be proof against both fire and earthquake, so the architects chose a dome-and-cupola design ². Still, the eastern part of the dome collapsed in an earthquake on 7 May 558 ³. The dome had been designed too flat, so it was raised by more than 20 feet and the supports of the great pillars were strengthened ³. The Encyclopaedia of Islam says the mosque has not suffered from earthquakes since the tenth century, and credits this largely to the buttresses that the last Byzantines and the Turks put up against three sides of the walls ⁴.

The first dome of Hagia Sophia was designed too flat and fell in an earthquake, and the builders raised it and strengthened its supports. Does that make you trust the building more or less than one that never failed, and why?

• Hagia Sophia: the building's story, from the first fire to the buttresses.
• The rebuilding of al-Aqsa: another building rebuilt after an earthquake.
• The earthquake of 425 AH: what fell in Ramla, Jerusalem and Ascalon.

Read about Hagia Sophia. Make a timeline of the earthquakes it names, what gave way each time, and what was built or changed afterward.