Sorry for the regulatory jargon below but for interest/information, some relevant agenda items at  the next WRC 2012 (all publicly available information from the ITU and CEPT/ERO websites)

1.10  (safety systems for ships and ports);

1.16 passive systems for lightning detection in the meteorological aids service, including the possibility of an allocation in the frequency range below 20 kHz

1.23 an allocation of about 15 kHz in parts of the band 415- 526.5 kHz to the amateur service on a secondary basis

The CEPT Conference Preparatory Group is developing the European Common Positions and Briefs for the WRC (as CEPT members the UK and German (etc) administrations will have agreed these)

Some extracts of CEPT positions already developed  for the items above:

1.10 CEPT supports the exclusive primary allocation to the MMS in the band 495‑505 kHz

1.16 CEPT supports a primary allocation for MetAids in the band 8.3 -11.3 kHz for passive applications.

1.23 that studies have taken into account CEPT proposals under agenda 1.10 in this frequency range; some (CEPT) administrations are of the view that an additional allocation of 15 kHz to the amateur service in the frequency band 415-526.5 kHz is not feasible because it would result in unacceptable harmful interference to the stations operating in the radiocommunication services allocated in the mentioned frequency band. There is no common position yet and discussions continue.

Further info on 1.16:

Although the maximum spectral emission of cloud to ground lightning strikes is centred between about 5 and 20 kHz, spectrum bandwidth of lightning stroke can reach several megahertz. The possible operation range of systems for lightning detection is determined by the used frequency band. In the frequency range 5-20 kHz the sky waves propagate over very large distances with relatively little attenuation. Thus, it is possible to receive the emissions from the cloud to ground strokes at thousands of kilometres from the stroke location.

The optimal frequency for ATD spectral emission measurements is around 9.766 kHz. However, the frequency 13.733 kHz is successfully used by the existing ATD systems for measurements, with a reduction of existing system performance seen at 9.766 kHz.

Long-range lightning detection using observations near 10 kHz has been performed in the UK since 1939, originally with a very manpower-intensive system measuring the direction from which signals were received, and then since 1987 with an automated Arrival Time Difference system (ATD) using the time differences of signal received to derive strike locations. Now, with modern sensor systems and communications it is possible to monitor the radio frequency received at the sensor in real time. Recent monitoring since [2004] has shown that it was not practical to use the frequency 9.765625 kHz at all the sensor sites, because of powerful transmissions near 10 kHz in some locations which prevented the operation of the passive sensors. Thus, the current system is operating at 13.733 kHz as noted in Fig. 1

The 3 dB bandwidth of existing lightning detection systems is approximately 2.5 kHz and hence an allocation of between 3 and 5 kHz bandwidth would be required

Currently the spectrum below 9 kHz is not allocated to any service but the following footnotes apply:

5.53        Administrations authorizing the use of frequencies below 9 kHz shall ensure that no harmful interference is caused thereby to the services to which the bands above 9 kHz are allocated.

5.54        Administrations conducting scientific research using frequencies below 9 kHz are urged to advise other administrations that may be concerned in order that such research may be afforded all practicable protection from harmful interference.

Because of the agenda item at the next WRC. I guess administrations (and Met organisations) are a bit jumpy about allowing precedents for other services before a decision is taken by the WRC. The chances of a common CEPT agreement on access conditions for amateurs before the WRC is dreamland stuff!! If each country waited, nothing would happen. Each administration is playing it by ear and trying to demonstrate it is complying with the Radio Regulations – however illogical the individual conditions might appear to amateurs.

Finally, has anyone on this forum seen proposals for a “New 500 kHz network”?

http://olivier.marsan.free.fr/N5NTW/NEW500KHZNETWORK.html