Animals navigate using a variety of sensory cues, but how each is weighted during different phases of movement (e.g. dispersal, foraging, homing) is controversial. Here, we examine the geomagnetic and olfactory imprinting hypotheses of natal homing with datasets that recorded variation in the migratory routes of sockeye (Oncorhynchus nerka) and pink (Oncorhynchus gorbuscha) salmon returning fro...

Paleomagnetic data on geomagnetic reversals are divided into two general categories: times of occurrence, and records of directional and/or intensity changes for transitions at individual locations. Despite considerable efforts expended in acquiring paleomagnetic reversal records, a detailed picture of the reversal process is still lacking, along with any means of clearly identifying when the m...

Acknowledgements The number o f in d iv id u a ls and o rg an iz atio n s who c o n trib u te d to th e work d escrib ed in t h i s paper i s so la rg e th a t some must accep t the a u th o r's thanks w ithout s p e c ific mention h e re. He must, however, e s p e c ia lly thank Dr. S ta te U n iv ersity o f Iowa, f o r suggesting the to p ic d iscu ssed in th e second p a r t of th e paper, f...

In this report we introduce the development of the WDC for Geophysics, Beijing included our activities in the electronic Geophysical Year (eGY) and in the transition period from WDC to WDS. We also present our future plans. We have engaged in the development of geophysical informatics and related data science. We began the data visualization of geomagnetic fields in the GIS system. Our database...

positive correlation at 65 +/5 degrees N geomagnetic latitude and altitudes 44-58 km in Figure 5. I am wondering about any possible significance of the large negative correlation, which is computed for 35 +/5 degrees S geomagnetic latitude and altitudes 50-62 km in Figure 5. Could the authors please elaborate on this as well? The mechanism for this is not yeat clear, but this is out of the scop...

The Japan Meteorological Agency (JMA) has developed an advanced system to monitor geomagnetic environments consisting of magnetometers and monitoring cameras. The new system calculates the magnetic moments and positions of sources of artificial disturbances and then visually identifies the sources. The intensity and location of a source of artificial disturbance are calculated assuming the sour...

Significant anomalous changes in the ultra low frequency range (approximately 0.01 Hz) were observed in both geoelectric and geomagnetic fields before the major volcano-seismic activity in the Izu Island region, Japan. The spectral intensity of the geoelectric potential difference between some electrodes on Niijima Island and the third principal component of geomagnetic field variations at an a...

The results show that both the direction and the intensity of the geomagnetic field can be sensed within the chamber of a Zeiss Cytopherometer. This suggests that electromagnetically induced fluid streaming might play a role in the perception of the geomagnetic field by organisms, although it is not clear at present in which organ the perception occurs. A basic requirement for such an organ wou...

The geomagnetic lunax daily variation field, L, was studied using all available results of lunar analysis of geomagnetic data from a total of 37 stations. Equivalent external (overhead) and internal (induced within the earth) electric current systems responsible for L variations with respect to dip latitude were estimated by the method of spherical harmonic analysis for each season. The externa...

[1] Available records of the magnetic indices Dst and ap together with standard observatory recordings of 1-min field levels were examined for the period preceding the earthquake of October 1989, centered near Loma Prieta, California. The magnetic records showed that the Fraser-Smith et al. (1990) report claiming the existence of a 100-s (ultralow frequency) geomagnetic field precursor signal a...