そりゃあ

Contraction of either それ (sore, “that”) or そいつ (soitsu, “he, she, that one”) with the topic marking particle は (wa).

• そりゃ (sorya)

そりゃあ • (soryā) 

1. (informal, regional) that's

   そりゃあそうよ！

   Soryā sō yo!

   That's right!

2. (informal, regional) he, she, that
   • 2014, Kazuhiko Tsuzuki, Osakana march‎, volume 1:

     でもなあ　そりゃあ悪(わる)いヤツには見(み)えないケドさ

     demo nā soryā warui yatsu ni wa mienai kedo sa

     but y’know, he didn’t seem like such a bad guy

Contraction of そう (sō, “so, like that”) and auxiliary verb だ (da) or variant such as や (ya) or じゃ (ja).

• そりゃ (sorya)
• そいや (soiya)

そりゃあ • (soryā) 

1. (informal, regional) certainly, of course, well

   そりゃあ知(し)らなかった。

   Soryā shiranakatta.

   Well you could have fooled me.

2. (informal, regional) just like that, right
   • 1997, Mariko Hayashi, Kimono o meguru monogatari, →ISBN:

     お父(とう)さんがうんと気(き)張(ばり)ってつくったから、そりゃあ、そりゃあ素(す)晴(ば)らしいもんやったわね。

     Otōsan ga unto kibaritte tsukutta kara, soryā, soryā subarashii mon yatta wa ne.

     Father went all out like that, nicely nicely he made something wonderful, right.