Erg (desert) - erg

Japanese: エルグ（砂漠） - えるぐ

… Deserts can be classified into sandy deserts, gravel deserts, and rocky deserts based on topography and geology. Sandy deserts are vast, flat, almost oceanic plains of sand, and the term erg, used in the western Sahara, is generally used. The average area of an erg is about 200,000 ^km2 , with the Rub' al-Khali Erg in the Arabian Peninsula covering more than 560,000 ^km2 . …

From the Sahara Desert

…There are three typical natural landscapes in the Sahara: sandy desert, plateau desert, and mountain desert. In sandy deserts, fine sand is blown by the wind into lowlands such as basins, forming a series of sand dunes called ergs, such as the Eastern Great Sand Dunes and the Western Great Sand Dunes. Ergs are considered the epitome of deserts, but in the Sahara they only account for 14% of the total area. …

*Some of the terminology that mentions "erg (desert)" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…　砂漠は地形･地質的に見て砂砂漠，礫（れき）砂漠，岩石砂漠に区分できる。砂砂漠は起伏の少ない広大ないわば砂の海原で，サハラ砂漠西部で用いられているエルグergの語が一般に使われる。エルグの平均的な面積は約20万km²で，アラビア半島のルブー･アルハーリー･エルグは56万km²以上を占める。…