Are we on unstable foundation?

The Soviets dug 40,000' or 12,000m into the earth in what would become the deepest hole in Earth. Water was unexpectedly found half way down as was a large quantity of hydrogen gas. The drilling mud that flowed out of the hole was described as "boiling" with hydrogen. Scientists discovered a lot from the Kola Superdeep Borehole. For starters, they realized they needed to update the temperature map for the Earth's interior, since they encountered temperatures much higher than expected.

Kola Superdeep Borehole - Wikipedia
Why Did the Russians Seal Up the Kola Superdeep Borehole?

Wondering what is underneath there? Are we on unstable foundations?

Where wast thou when I laid the foundations of the earth? declare, if thou hast understanding. Who hath laid the measures thereof, if thou knowest? or who hath stretched the line upon it? - Job 38:4-5

Depth perspectives...

Mount Everest ---- 08.9 km or 5.5 miles high
Mount Whitney --- 06.2 km or 3.9 miles high
Mount Fuji --------- 03.8 km or 2.3 miles high
Sea Level----------
Titanic Wreckage -03.8 km or 2.5 miles deep
Deepest Mine ---- 03.9 km or 2.5 miles deep
Mariana's Trench - 10.9 km or 7.0 miles deep
Kola SD Borehole - 12.3 km or 7.5 miles deep

Are we on unstable foundation? is this the cause for the many earthquakes and volcanic activity? At what depths are the magma flow? Could this cause more sulfur laden eruptions and cause our planet to become super hot like Venus?

 

Boreholes… We didn’t go far! And to add a journey to the Earth's mantle

Mount Everest ---- 08.9 km or 5.5 miles high
Mount Whitney --- 06.2 km or 3.9 miles high
Mount Fuji --------- 03.8 km or 2.3 miles high
Sea Level----------
Titanic Wreckage -03.8 km or 2.5 miles deep
Deepest Mine ---- 03.9 km or 2.5 miles deep
Mariana's Trench - 10.9 km or 7.0 miles deep
Kola SD Borehole - 12.3 km or 7.5 miles deep
Earth Mantle -------- 100 km or 60 miles deep
Earth Core ——3,000 km or 1,800 miles deep
Earth Center— 6,500 km or 4,000 miles deep

The journey to the Earth's mantle did not even get close. An unexpected heat - Things did not go as well as the Russian team had hoped for. As they dug deeper, they had no idea they were about to come in contact with something unexpected. As their drill slowly inched closer to the earth's center, a complete change occurred.

The first change was that the temperature inside the borehole started to change. As they dug further, the heat started to shoot up faster. By the time they were nearing their target of 49,000 feet, the heat in the hole was already 180 °C (356 °F) to a full 80 °C (176 °F). The team did not expect this much heat.
Plastic rocks - The heat is not the only strange thing the Russian team noticed as they dug further into the borehole. The researchers found that the rocks at those depths were less dense. And because of this, the rocks reacted differently to the higher temperatures. For instance, the rocks had an almost plastic-like texture. This strange texture eventually became a problem because it made it almost impossible to drill through the rocks. Not only that but the heat and the rocks were too much for their machine. It was at this point that the Russian team started to think that their drilling toward the center of the Earth would be over soon. Their equipment would not last long with the extreme heat and the plastic-like rocks. - A Dig Towards the Core of the Earth Uncovers a Lot of Scientific Secrets - Greedy Finance