So, unfortunately, your camera is part of an abandoned system. No more lenses nor bodies are being made for 4/3 DSLRs, and while some adapters exist, you don't have a large enough investment to be worrying about that (the adapters will cost more than the value you'd get out of them. You should have a DSLR though, because as good as the mirrorless cameras are now, they still struggle with really long lenses and snapping to focus compared to a good DSLR, and at the end of the day the total system weight is roughly the same if not heavier for a mirrorless set, as it's dominated by lens size. That being said, while the controls may be different, the techniques you use on your current camera translate directly to a new one.
Keeping in mind I'm on the Nikon side of the fence, not Canon or Pentax, so I don't know what their offerings are, but if I were buying, from scratch, today, for a cruise to Alaska, I'd get:
- Nikon D7200
- Nikon 10-24 mm f/3.4-4.5G DX
- Nikon 16-85 mm f/3.5-5.6G DX VR
- Nikon 70-300 mm f/4.5-5.6G VR
- Nikon 35 mm f/1.8G DX
That's a crop sensor camera (Nikon calls them DX), a wide angle zoom lens, a normal zoom lens, a telephoto zoom lens, and a fast prime lens for low light. I'd also rent one of the big teles if I were going to Denali, but those take a TON of technique and practice, not to mention a monopod; the 70-300 is probably the limit of what most people can handle easily.
If I were on more of a budget, I'd get:
- Nikon D5300 or D5500
- Nikon 18-55 mm DX VR II
- Nikon 55-300 mm DX VR
You lose on the wide end (although you can add a lens to fix that, as well), but it still gets you out to 300 mm, with a very good autofocus system, but does it at less than half of the cost. Oh, and it's *considerably* lighter, the D5500 in particular is a pixie-weight camera with a new poly/carbon fiber body. Also, you can often find a bundle for the above kit for around the $1,000 mark.