I’ve experienced it, and maybe you have, too. In mid-flight, the seat-belt light comes on and the pilot announces that the airplane is entering an area of turbulence. Shortly afterward, various shakes and jolts start bumping you around, and while it can be unnerving, you knew it was coming and you’re not too concerned. Then, with no warning comes a WHAM, a sickening two- or three-second drop, as a particularly powerful air pocket rocks the plane. There’s a lurch in your stomach and you think for an instant: this could be really bad.

Yesterday, at least 800 jobs disappeared from law firms in the US and the UK — there may well have been more, because rumours of “stealth” or “performance” layoffs have been circulating for awhile. White & Case accounted for half those firings, divided equally between lawyers and staff — but remarkably, the firm also talked openly about a partnership cull too,  something I suggested last week was imminent. In addition, Morgan Lewis not only joined the layoff parade, but also postponed the start date for its incoming lawyers by one year, meaning the firm will have no first-year lawyer class in 2009.

These are just the most notable developments in one day from the largest firms — the mainstream legal media isn’t looking at what’s happening to small, mid-size and regional firms. But the lurch I talked about isn’t just from these numbers, or even from the thousands of layoffs that preceded them: it’s from a couple of hard realities hitting home. One, job losses in the legal profession are just getting started — this thing is picking up speed and no one knows where or how it will end. And two, “this thing” is a lot more than a recession.

Put those law firm numbers — vanishingly small in the greater scheme of things — in the context of some truly sobering economic news worldwide. Evidence is accumulating that our situation is leaving “recession” behind and is rapidly approaching something that requires adjectives like “Great.” But this isn’t a depression, capital-D or otherwise — it’s something altogether new. The New York Times identifies it as a fundamental reshaping of the economy in the US and other western countries, a shift into different types and means of  productivity.  Jeff Jarvis calls it a Great Restructuring: “It’s more than jobs lost and companies folding. It’s a new economy built on a new society that we are only just beginning to recognize if not understand.”

Many underlying beliefs about how economic value is generated are simply falling away, and we don’t yet know what will replace them — all we know is that it’ll be different from what we had before. That’s why many of the legal job losses we’re seeing, in firms of all sizes, aren’t temporary layoffs that will return when the recession ends. They’re eliminations — positions that won’t come back, because the underlying mechanics of value in legal services are changing and the new environment that emerges from this crisis won’t require them.

The first wave, as we’ve seen, is the beginning of the end of large groups of associates in law firms. But we’re also seeing transactional legal work transformed  by online document assembly, changing the face of smaller practices and tapping into new latent markets. We’re seeing law firm partners find competitive and personal benefits by becoming virtual lawyers. We’re seeing that large firms themselves require reconstruction at the business-model level, and some of the problems are so severe that the solution is not realignment or re-engineering, but replacement. And we can foresee major changes to lawyers’ regulatory environment and firms’ subsequent evolution into full corporate entities.

The frightening thing — or the exhilarating thing, depending on how you view it — is that nobody knows what’s going to happen next. This really is an unprecedented development. The legal industry has been through recessions before, and it has a pretty decent idea of how to cope with those. But there are no blueprints for a fundamental reordering of the rules of business — both our clients’ businesses and our own. The Wall Street Journal notes that the most significant employment crisis underway right now is in the professional sector, and that “we are totally unprepared for this phenomenon.”

I don’t know what to tell you at this point. There’s not much you can do during the earthquake itself, beyond trying to keep your balance and hoping nothing large will collapse on top of you. Don’t rely on previous procedures to get  through this, but do rely on your professionalism and commitment to service. Invest in anything that will enhance your ability to collaborate with others. Stay as close to your clients as you can, and grope with them towards what new definitions of value and service in the law will look like — under no circumstances let them arrive at those conclusions on their own. And remember that we’re approaching a moment of maximum possibility in the law — you’re getting closer to being able to define the terms of exactly the legal career you want. Everything’s up for grabs — so grab something.

Note to regular readers: I’ll be out of town for several days and hope to return to blogging later next week.