Firstly there are two types of parachutes, the old fashion "roundies" and the modern ram air square chutes.
I presume that the hole in the top of round parachutes creates an airflow through the canopy during deployment (opening) which reduces the chances of a malfunction during this critical phase. If not for this airflow, the flow of air around the unopened canopy would create an air pressure differential between the inside and outside of the fabric and the resultant suction would tend to keep the canopy in a collapsed state, not a good thing to happen as the ground rushes up at you.
It would also make the canopy more steerable.
The holes in the front of a square canopy are sealed at the back of the chute and allow the chute to pressurise into its aerodynamic shape.
The vent on top of the parachute helps air go through. If you didn't have a vent at the top you would be floating in the same place. The vent makes the parachute go down slowly but not fast enough to where you would drop.
A hemisphere design parachute typically consists of a canopy made of two semi-circular panels sewn together, a suspension line system connecting the canopy to the harness, a deployment bag to contain the parachute during packing, and a pilot chute used to deploy the main canopy. The parachute design ensures efficient deployment and proper inflation for a safe descent.
The main parts of a parachute are the canopy (the fabric that catches the air to slow descent), the lines (cords that connect the canopy to the harness), the harness (the straps that attach the parachute to the user), and the deployment mechanism (the system that releases the parachute to open).
The canopy.
It could be a speaker grille.
Usually at the top or close to the top. It is linked to the vent (above the vent) where magma erupts.
Vent .
There is no such thing as a "hypothermal" vent.
fuel vent valve is on the top of the gas tank
To get a boost from a steam vent, walk to the middle of the steam vent and then jump up. If you jump onto the steam vent from the top, it won't boost you up as high.
If the volcano is active, there may be vents around the volcano as well as on top. A vent is where volcanic material (lava, steam, ash) is being released.
Unless your a bird you really cant.the only way i can think of is climbing to the top of a moutin with a parachute and jumping and hopefully you can control that parachute.