Does Dead Space have many jumpscares?

Yes the game has many "jump scares" depending on what you deduce as a jump scare

If you mean pretend dead bodies animating in front of you when you least expect it or things coming up behind you and you don't realize to the last second.

Then yes there is many.

The atmosphere overall is what makes this game scary, the jump scares just break that teeth grinding tension.

OH YEAH! There are multiple jump scares set in the right places, but what is scary for people may not be scary for others. But there still are lots of jump scares. And they usually always work for unsuspecting players!