During most library operating hours, you may come to the library and receive in-person assistance with research from a librarian.
You may sometimes wish to consult with a librarian without actually coming to the library. As shown in the following image, the library website offers a number of options under the heading Ask a Librarian.

If the Chat with a Librarian icon is green that indicates that a librarian is now available to help you.
To identify the library's liaison for your academic major, on the library's website, scroll down until you see the pictures of the reference librarians (as shown in the image below).

Clicking on any of the names or photos will bring up a web page identifying the departments for which each librarian is liaison.