Let's consider the piano version of Moldau/Vltava from Smetana, the first two measures for example:

[!["Moldau" mm. 1–2 with staccato, accented eighth-note chords circled][1]][1]

What should be the duration of the blue circled notes, as expressed in units of an eighth note:  
Should it be *less* than an eighth note, or *equal* to an eighth note?

Is it staccato or something else?  
If this is *less* than an eighth note, then would that mean the right-hand circled notes do not "fill" the rest of the measure? (and if so, why isn't there some sort of silence added to the score?)


[1]: https://i.sstatic.net/US5jE.png