Recently Ariya added a patch for allowing the Earth to continue spinning for a while after dragging the surface.

This behavior can currently only be switched off via a settings file.(file: ~/.config/kde.org/Marble\ Desktop\ Globe.conf in the Qt Version, ~/.kde4/share/config/marblerc or ~/.kde/share/config/marblerc in the KDE Version , look for "kineticScrolling=true" inside).

Please integrate this UI file:

http://devel-home.kde.org/~tackat/MarbleNavigationSettingsWidget.ui

to allow the user to toggle this setting.

Most likely the settings/config key needs adjustment for this:
currently the feature is part of the MarbleWidget group and should probably be moved to Navigation.