What is the shape of Earth according to Hindu scriptures?
It is widely believed that the round shape of Earth was known for a long time. Although, is this mentioned at any specific place?
In the Aitareya Brahmana of RigVeda 3.44
“The Sun does never set nor rise. When people think the Sun is setting (it is not so). For after having arrived at the end of the day it makes itself produce two opposite effects, making night to what is below and day to what is on the other side…Having reached the end of the night, it makes itself produce two opposite effects, making day to what is below and night to what is on the other side. In fact, the Sun never sets….”
Similar verse also occurs in Śrīmad-Bhāgavatam 5.21.9 as:
यत्रोदेति तस्य ह समानसूत्रनिपाते निम्लोचति यत्र क्वचन स्यन्देनाभितपति तस्य हैष समानसूत्रनिपाते प्रस्वापयति तत्र गतं न पश्यन्ति ये तं समनुपश्येरन्
yatrodeti tasya ha samāna-sūtra-nipāte nimlocati yatra kvacana syandenābhitapati tasya haiṣa samāna-sūtra-nipāte prasvāpayati tatra gataṁ na paśyanti ye taṁ samanupaśyeran
People living in countries at points diametrically opposite to where the sun is first seen rising will see the sun setting, and if a straight line were drawn from a point where the sun is at midday, the people in countries at the opposite end of the line would be experiencing midnight. Similarly, if people residing where the sun is setting were to go to countries diametrically opposite, they would not see the sun in the same condition.
The above verses clearly shows that earth should be of round shape.
It becomes more crystal clear from YogaVasistha MahaRamayana:
Chapter 30 Description of Universe
Rama said, “Tell me sage, why do we refer to up and down, forward and backward, if there is no such thing in space and nature?”
10 Vasishta said:—
There is only one space enveloping all things. The worlds seen in the infinite and indiscernible womb of emptiness are like worms moving on the surface of water.
11 All these bodies that move about in
the world by their lack of freedom are thought to be up and down relative to our position on earth.
12 So when there are ants on an earthen ball, all its sides are reckoned below that are under their feet, and those as above which are over their backs.
13 Such is this ball of earth in one of these worlds, covered by vegetables and animals moving on it, and by gods, demons and men walking upon it.
Thus the shape of earth is round/spherical as per our Scriptures.
Edit Update (Thanks for @Surya for giving link):
Most basically the term earth and Geography are represented by the word Bhugol. Where Bhu stands for land and earth and 'Gol' means round/sphere. Some of the references from scriptures:
न वै महाराज भगवताे मायागुणविभूतेः काष्ठां मनसा वचसा वाधिगन्तुमलं विबुधायुषापि पुरुषस्तस्मात्प्राधान्येनैव भूगाेलकविशेषं नामरुपमानलक्षणताे व्याख्यास्यामः । (Śrīmad-Bhāgavatam 5.16.4)
भूगाेलं सगिरिसरित्समुद्रसत्वम् । (Śrīmad-Bhāgavatam 5.25.12)
In above word 'भूगोल (Bhugola) is used. Thus the most basic etymology also proves the fact.