I'm trying to do the Mapbox design. There is a fog on the globe in Mapbox. I use "box shadow inset" for the same effect. But because I give high value, there are various fluctuations.
My Try;
The effect I use to give the fog;
<svg>
<defs>
<filter id="shadow">
<feFlood flood-color="gray" />
<feComposite operator="out" in2="SourceGraphic" />
<feMorphology operator="dilate" radius="20" />
<feGaussianBlur stdDeviation="50" />
<feComposite operator="atop" in2="SourceGraphic" />
</filter>
</defs>
</svg>
What I Want To Do (Mapbox, hollow of fog cloud);