How can I stop pages from scrolling with an empty hyperlink jump?

How can I stop pages from scrolling with an empty hyperlink jump?

On Tumblr and a few other websites, when you scroll X amount of pixels
vertically, an arrow appears that takes you to the top, with a hyperlink
jump. (I believe that is the correct term.) They're basically <a> tags
with a href attribute of #.
In my opinion, hyperlink jumps are a lot 'cleaner' looking than your
"javascript:void(0); more code goes here..."
In addition to the hyperlink jump on Tumblr to scroll to the top, there
are many pieces of GUI elements in web pages that use a "blank hashtag
link", but they aren't used for scrolling, but rather, clean, empty
hyperlinks. When THEY are clicked on, they do not scroll the page to the
top, but instead, call a JavaScript function to display an element, do a
task, etc.
As far as I know, these links have no JavaScript events attached to stop
scrolling. (Ex. onclick="window.event.preventDefault()".
Am I missing something?
EDIT:
My personal issue that I'm facing is that I want to have an empty
hyperlink (on my top navigation bar), but I don't want the page to scroll
to the top when it is clicked on (the default action in probably every
browser). How to fix with/without JavaScript?
EDIT:
Possible fix for this issue. Non-JavaScript: Fix an element's position
with the coordinates (0,0), and link the empty links to it. (But it still
wouldn't be empty :()