Image header displaying differently in Explorer vs. Chrome

Hello,

I’m running a child theme of Fashionista and recently uploaded a new header image. Before, the image was the correct size on both Google Chrome & Internet Explorer.

Now, however, the image is the correct size only on Chrome and expands past the page margins on Explorer.

I don’t know how to correct the sizing in Internet Explorer– please help!

Site: globewomen.org/globalsummit/