Yes it is.
1. Go to your profile, write something to the calendar secret field.
2. Go to the calendar page on your site. There will be a new field called Calendar subscription URL. Copy the text within.
3. Go to Google calendar, an on the left side press the triangle next to Other Calendars, and select Add by URL.
4. Paste the text you copied in step 3 into the URL field.
5. Press Add Calendar