How deep are deserts like the Sahara and Arabia?

Deserts are not defined by their being sandy. They are defined by absence of rainfall. Or at least a deficit of rainfall against evaporation. read more

The Arabian Desert is a vast desert wilderness in Western Asia. It stretches from Yemen to the Persian Gulf and Oman to Jordan and Iraq. It occupies most of the Arabian Peninsula, with an area of 2,330,000 square kilometers (900,000 sq mi). It is the fourth largest desert in the world, and the largest in Asia. read more

Arabian Desert The Arabian Desert, the largest desert in Asia, covering an area of about 900,000 square miles (2,300,000 square km). Encyclopædia Britannica, Inc. The Arabian Desert. read more