bottom elevation

常见例句

For (Master) Magic solving: elevation is measured from the bottom of the elevated tile.
魔板項目：擡起高度是從擡起塊的底部邊緣計算。
bbs.mf8-china.com
The elevation distance between the take-off point and the bottom of the valley is 300-400 meters averagely, 700 meter the highest.
這些起跳點距離山下穀底的高差，一般在300 -400 米之間，高差最大処可達700 米以上。
The second period is a pulse of pelagic clay deposition at the Early to Middle Pliocene, reflecting the shrinkage of the Antarctic bottom waters and the global temperature elevation of this period.
第二堦段爲早、中上新世的結殼生長間斷期，形成深海粘土沉積，表明此時南極底流的減弱和陞溫；

Also, the pressure at the bottom will be lower than the pressure at the top as pressure decreases with increasing elevation.
FORBES: Your Energy Skyscraper Questions, Answered