The Island of Jambudvipa
The planetary system known as Bhū-maṇḍala resembles a lotus flower, and its seven islands resemble the whorl of that flower. The length and breadth of the island known as Jambūdvīpa, which is situated in the middle of the whorl, are one million yojanas [eight million miles]. Jambūdvīpa is round like the leaf of a lotus flower.
Jambudvipa, the eight mountains and the nine Islands of Bharata Varsha
In Jambūdvīpa there are nine divisions of land, each with a length of 9,000 yojanas [72,000 miles]. There are eight mountains that mark the boundaries of these divisions and separate them nicely. Amidst these divisions, or varṣas, is the varṣa named Ilāvṛta, which is situated in the middle of the whorl of the lotus. Within Ilāvṛta-varṣa is Sumeru Mountain, which is made of gold. Sumeru Mountain is like the pericarp of the lotuslike Bhū-maṇḍala planetary system. The mountain’s height is the same as the width of Jambūdvīpa — or, in other words, 100,000 yojanas [800,000 miles]. Of that, 16,000 yojanas [128,000 miles] are within the earth, and therefore the mountain’s height above the earth is 84,000 yojanas [672,000 miles]. The mountain’s width is 32,000 yojanas [256,000 miles] at its summit and 16,000 yojanas at its base.
Locating Bharata Varsha
The nine islands of Bharata Varsha are located on the Southern tip of Jambudivpa, Bharata Varsha is said to be bow shaped, each island is separated by salt water ocean. Our earth Island Bharata Khanda is mentioned in the Mahabharata.
(Jambhu-khanda-parva of. Bhishma Parva): “This Bharata–khanda (earth) is called. Sudarshana-dwipa, since it looks beautiful to the eyes of the onlookers. Being circular it looks like the disk of the Lord and it is attached to the cycle of time in the form of a disk presided over by Bhagavan Sudarsana.
More information on Bharata Khanda can be found in the Surya Siddhanta section of this site.