English Idiom of the Day – Tip of the Iceberg
Tip of the Iceberg
If something is said to be 'the tip of the iceberg' it means that something is only a small part of a much bigger problem. The 'tip of the iceberg' is the part of a problem that can be easily observed, but not the rest of it, which is hidden.
Example: The problems that you see here now are just the tip of the iceberg. There are numerous disasters waiting to happen.
Origin: This idiom comes from the fact that only the tip of an iceberg can be seen and the rest of the iceberg, which is much larger, is underneath the water and cannot be seen.